David Cooke’s victory in the 66th Illinois Open was a run-away. His five-shot victory at Royal Melbourne, in Long Grove, was the biggest since Gary Hallberg’s triumph in 1977.

Though the tourney lacked suspense, it was loaded with emotion and another historical touch. Cooke was the first amateur to win the title since Brad Benjamin in 2009. Hallberg, who went on to a solid career as a touring pro, was also an amateur when he won at Elgin Country Club 38 years ago.

Cooke’s win, though, was more about family than it was about history. Last Dec. 23 he lost his younger brother Chad, a 20-year old basketball player at Charleston Southern. He passed away from an apparent heart disorder while playing in a pickup basketball game.

“He was a strong encourager of everybody,’’ said David Cookie. “I knew he’d want me to keep playing. I tried to focus on that and think about positives. I have great memories of my little brother. I wish more than anything that we could have him back.’’

Chad was occasionally David’s caddie in tournaments. His older brother Jay, 34, came from South Carolina to work as David’s caddie in the Illinois Open and they were followed by their parents, grandparents and other family members and friends who walked with them in the final round.

“It was an emotional win,’’ said Cooke, who will enter his senior year at North Carolina State in the fall. “It’s been a rough last year, and it meant a lot to me and my older brother that everyone was here.’’

Cooke grew up in Bolingbrook, and his family moved to Lisle several months ago. He had never led a tournament over night until he shared a one-stroke lead with Brad Marek of Arlington Heights heading into Wednesday’s final round of the Illinois Open.

“There were nerves on the first tee,’’ Cooke admitted, but they went away quickly when Cooke hit a pitching wedge from 144 yards to six feet and then rolled in a putt for eagle at No. 1. He made birdies on the next three holes as well and coasted from there.

Cooke had been in the next-to-the-last group in the final round of the Illinois Open in 2012 and 2013 but fizzled down the stretch. He didn’t play in the event last year and basically had only Vince India, a Web.com Tour player from Deerfield, as a challenger in the final round.

“David played great,’’ said India. “I certainly played fine. I shot 5-under, but what are you going to do?’’

Cooke shot 63 on Wednesday and finished at 16-under-par 199 for the 54 holes. India shot 67 but did claim the $12,500 check for being low pro.

“This win was a big motivator for me,’’ said Cooke. “It showed me I could compete with pros. It helps me know that I’m on the right path.’’

Cooke’s round wasn’t the best of the day. Early starter Matt Weber, an Indiana University sophomore from Hinsdale, posted a 62 to tie the course record but he finished in a tie for 13th place.

Monday turned out a big day for the golfers at Conway Farms – but an even bigger one for David Lawrence. The Moline golfer shot a 9-under-par 62 at Royal Melbourne in Long Grove. That’s the lowest round in the 66-year history of the Illinois Open.

Lawrence, who has been playing golf’s mini-tour since attending Eastern Illinois, wasn’t the whole show on the first day of the 54-hole competition. Three players shot 66, among them Conway Farms head professional Matt Slowinski. His hot round came on the same day that Zach Johnson won the British Open in Scotland. Johnson also has ties to the Lake Forest club, having won the PGA Tour’s BMW Championship there in 2013.

Johnson’s victory at St. Andrews was good news for Slowinski, with the BMW Championship returning to Conway Farms in September.

“I’m glad he won it. It’ll be good for our event as well,’’ said Slowinski, who had a strange round, despite the good result.

“You never feel good hitting a provisional on the first hole,’’ he said, “but I wound up making a 15-footer for bogey and got the momentum going from there.’’

The momentum reached a crescendo on his last shot, when Slowinski holed a gap wedge from 125 yards for eagle to finish off his round. That left him in a three-way tie for second with amateur Nick Hardy of Northbrook and Deerfield’s Vince India, who has spent the last two seasons on the Web.com Tour.

With 258 starters – 151 of them amateurs, this is the biggest-ever Illinois Open. The Illinois PGA changed the format this year, boosting the field from last year’s 156 and going to two sites for the 54-hole finals. Half the field played at Royal Melbourne, in Long Grove, and the other half at Hawthorn Woods Country Club.

“I like (the new format),’’ said Slowinski. “It’s good to see more people in the field, and it’ll make the event better.’’

Slowinski opened his title bid at Royal Melbourne and plays at Hawthorn Woods on Tuesday. That was encouraging for him because his best Illinois Open was a tie for fourth when the event was contested at that course from 2008-11. Hardy and India also posted their low scores at Royal Melbourne.

Hardy is in the midst of a torrid schedule. He finished third in the Illinois State Amateur last week at Panther Creek, in Springfield. After the Illinois Open he has the Western Amateur at Rich Harvest, in Sugar Grove, and the U.S. Amateur, at Olympia Fields, on his August schedule.

The field will be cut to the low 70 and ties (up from the 50 and ties from previous years) after Tuesday’s rounds at both courses. The final 18 will be at Royal Melbourne on Wednesday.

SPRINGFIELD, IL. – A year ago Naperville’s Ray Knoll and Northbrook’s Nick Hardy battled through four playoff holes before Knoll won the Illinois State Amateur title. Knoll couldn’t repeat this year, and Hardy didn’t win, either, but nobody played better than those two during this year’s final round at Panther Creek Country Club on Thursday. They were spectacular.

Tee-K Kelly, a Medinah member from Wheaton, won his second Illinois Am title in a three-hole aggregate score playoff with 18-year old Conor Dore of Chicago, but that result was somewhat overshadowed by the record rounds posted by college stars Knoll (Iowa) and Hardy (Illinois).

Hardy matched the course record of 6-under-par 65 but wound up third. For the final 18 holes Knoll was even better. He posted what’s believed to be the lowest round in the 85-year history of the Illinois Am – an 8-under 63 – and it included what’s believed to be the first albatross in the event’s history as well. Chicago District Golf Assn. officials couldn’t confirm the apparent milestones because much of the tournament data was lost in weather-related damage several years ago.

Knoll, who enters his junior year at Iowa in the fall, saw his title defense evaporate after shooting a 75 in the morning 18 holes of the 36-hole final day. Making six birdies in the first 11 holes in the afternoon, all from the four to 10-foot range, Knoll climbed the leaderboard but saved his best for No. 15, a 576-yard par-5.

“Going to the last round I knew I didn’t have a chance to win, but I was playing good and just tried to be aggressive,’’ he said. So, at No. 15 he blasted a “perfect’’ drive, then studied the possibility of going for the green with his second.

“I didn’t know what my yardage was because my rangefinder died when I was on the 10th hole,’’ he said. “I stepped it off from the 200-yard marker and found the yardage was 267 yards plus three more to the pin. I hit a high draw with my 3-wood and swung a little harder because that distance was a little out of my range.’’

Well, actually it wasn’t. His ball landed on the front of the green, bounced once and rolled into the hole. It was his second albatross, the first coming on a 6-iron shot from 191 yards while playing an informal round with his father at Hickory Ridge in Carbondale.

This one elevated Knoll to under-par status for the tournament and into a tie for sixth place. He wasn’t close to the front-runners — Dore, who enters his freshman year at Southern Illinois-Edwardsville in the fall, and Kelly, who won the title for the first time in 2013. They finished the regulation 72 holes at 9-under-par 275.

Dore, who ruled the Chicago Public League for three years while at Whitney Young, made three costly bogeys down the stretch – the first at No. 17 in regulation and the last two in the final two holes of the playoff. That made Kelly, a senior-to-be at Ohio State, the champion off his three pars in the extra session.

SILVIS, IL. – Bring on the British Open. Jordan Spieth is more than ready to claim the third leg of what could be the first modern day golf Grand Slam.

The 21-year old Masters and U.S. Open champion won the John Deere Classic for the second time without his best stuff on Sunday, then boarded a jet with a batch of other players for this week’s third major championship of the year at storied St. Andrews in Scotland.

Spieth started the final round of the JDC with a two-stroke lead but trailed by four with six holes to go. Tom Gillis, a 46-year old journeyman without a win in 171 starts on the PGA Tour, got hot early and posted a 7-under-par 64. That made him the clubhouse leader at 20-under 264 for the regulation 72 holes.

Gillis, who played four groups in front of Spieth, made a costly bogey at the 16th and Spieth made three birdies to force a playoff. The extra session went two holes, Spieth winning with a par after Gillis hit a tee shot into the right rough and his second into a pond on the left side of the fairway.

Spieth started the tournament with a par-71 round, showing rust after a two-week layoff. He was hot in rounds two and three, shooting 64 and 61, then cooled off again on Sunday.

“I didn’t have my best for the first 12 holes or so, but it’s very satisfying to have stretches like that and still come out with the win,’’ he said. “This gives me a lot of momentum to draw on.’’

Sunday wasn’t just a duel between Gillis and Spieth. Danny Lee, winner of the Greenbrier Classic – last week’s PGA Tour stop, and hometown favorite Zach Johnson also were in the hunt. Unusual circumstances derailed both.

Lee went brain-dead at the fourth hole. With the course soggy from heavy rains on Saturday, the lift, clean and place rule was invoked. That wasn’t the case on Sunday. Lee picked up his ball “without just thinking.’’ His caddie gave him the bad news – a one-stroke penalty that eventually kept him out of the playoff.

Johnson might have been in the playoff as well. He was lining up a birdie putt on the No. 16 green when what sounded like a gunshot forced him to jump back. It apparently came from a pontoon boat on the nearby Rock River and security officers quickly rushed to the scene.

“I don’t know if it was a backfire from a boat or a firecracker or what,’’ said Johnson, who was clearly shaken by the incident but didn’t blame his finish on it. He left his 35-foot birdie putt two feet short but salvaged par and wound up tied for third with Lee, one stroke out of the playoff.

Gillis was on the brink of being the latest first-time champion at the JDC – there have been seven just since 2000. He carried a No. 643 world ranking into the week and was No. 194 in the FedEx Cup standings and No. 199 on the PGA Tour’s season money list. In finishing second he earned a seat on the jet to the British Open.

“The week was a success overall,’’ he said. “I haven’t shown a whole lot of form coming back from shoulder surgery. I missed four months this year, and you start to wonder how much more is there. After what I saw this week I’d say maybe I’ve got some time left.’’

Spieth has much more of it, of course. He left for St. Andrews as the sixth player to have won the first two majors championship of the year. The only Grand Slam in golf history was by Bobby Jones in 1930, but his four wins were in different tournaments – the U.S. Amateur and British Amateur replacing the Masters and PGA Championship, which are included now. Jones’ other wins were in the U.S. Open and British Open.

“I’ve heard St. Andrews is playing softer than usual, which is kind of nice for having come from here,’’ said Spieth. He has been at St. Andrews only once, for two days over three years ago. He loved the setting, but was widely criticized the last three weeks for not skipping the JDC to allow for more preparation in Europe with such a big title on the line.

“I really didn’t care about that,’’ he said. “I came here for a reason, and we accomplished that reason. Certainly we have some momentum going into next week.’’

SILVIS, IL. – Another John Deere Classic hasn’t been won yet and the British Open – the third leg of golf’s Grand Slam — is next week’s target. Still, Jordan Spieth’s game is good enough right now to win them both, no doubt about it.

That was underscored on Saturday when the 21-year old Masters and U.S. Open champion climbed to the top of the leaderboard in the JDC at TPC Deere Run.

Spieth arrived at the site of his first PGA Tour win of 2013 off a two-week break, one of which included not touching a club. Rustiness showed in Thursday’s first round, when he shot par 71 and was mired in a tie for 101st place.

The rust disappeared on Friday when Spieth shot 64 and moved into a tie for 16th, and Saturday the sharpness was even better. Spieth posted a 10-under-par 61, giving him a two-stroke lead to take into Sunday’s final round.

Could his game be peaking at the perfect time? It certainly seems like it. At least Spieth could do no wrong on his 2-3-3 finish on Saturday. The deuce at the par-3 16th was followed by an errant tee shot at the par-5 17th. Spieth found himself deep in the left woods.

“There wasn’t a big window,’’ he said, “and I needed to hit it 170 to carry the bunkers.’’

He did that with a 5-iron, a club chosen for the loft it could produce rather than the length. He was still left with a 105-yard left-to-right third shot to the green. Club choice was tricky, but Spieth pulled out a sand wedge and miss-hit it. The “miss-hit,’’ though, dropped into the hole for an eagle.

“Maybe that was the wrong club, to be honest,’’ said Spieth. “I had a lot of good breaks coming in when I didn’t hit good shots off the tee.’’

The birdie on the finishing hole resulted in the lowest round of Spieth’s meteoric career.

As good as Spieth has been the last two days, this JDC is far from his. Danny Lee, winner last week at the Greenbrier Classic, shot 62 in the third round after playing the first two in Spieth’s threesome. Lee called Spieth’s blazing finish “a little ridiculous’’ but admitted “he’s winning everything right now. I’ll just go out and play and see what happens. All I know is a lot of people will be watching us, and I can’t wait to see what happens.’’

Lee has his own shot at history before he, Spieth and a batch of others board the jet from the Quad Cities Airport to Scotland on Sunday night for the British Open at St. Andrews. If Lee wins on Sunday he’ll be the first player since David Duval in 1997 to claim his second PGA Tour win a week after winning his first.

The focus in the final 18, however, will be on Spieth who was widely second-guessed for playing the JDC instead of going to Europe a week early and tuning up at the Scottish Open with a shot at the Grand Slam on the line.

Spieth has no regrets about coming here. He replaced the hybrid in his bag with a driving iron as part of his British preparation, and was pleased with the results. Plus, the weather on Saturday was helpful, too. There were two weather delays, but they didn’t keep Spieth off the putting green.

“I was embracing practice in the rain because we’re sure to see that next week,’’ he said.

For now, next week can wait. Spieth has more than just the red hot Lee to beat on Sunday. Lee will be Spieth’s playing partner for the third time this week but Justin Thomas, leader after the first two rounds, and Johnson Wagner are shot behind Lee and hometown favorite Zach Johnson, the 2012 champion, is another swing back.

`There’s a lot of young players coming out who aren’t scared to win,’’ said Spieth. “It’d be great to win again at a place that’s special to me.’’

SILVIS, IL. – Second-guessers abounded when Jordan Spieth announced he would return to the John Deere Classic for his last tuneup tournament before next week’s British Open.

A large segment of the world-wide golf community felt Spieth was short-changing himself by not heading to Europe a week ahead of his bid for a third straight major championship. After all, he would have more time to combat jet lag if he played in the Scottish Open instead of the event where he won his first PGA Tour title at age 19 two years ago.

With titles in the Masters and U.S. Open already clinched, Spieth is halfway toward an unprecedented Grand Slam of the four biggest tournaments. (The fourth is the PGA Championship at Wisconsin’s Whistling Straits course next month).

Those second-guessers seemed to have a case when Spieth had a mediocre showing in Wednesday’s pro-am at TPC Deere Run and followed with a par 71 in Thursday’s first round of the JDC. That left him tied for 101st place and in danger of missing the 36-hole cut.

Spieth, however, silenced those second-guessers on Friday when he posted a 7-under-par 64 and climbed all the way into a tie for 16th place – four strokes behind 22-year old Justin Thomas, the leader going into Saturday’s third round after posted 12-under 130 for the first two rounds. Spieth’s Grand Slam preparations – as well as his chances of winning the JDC again — don’t look so questionable now.

“Today was a big step forward,’’ said Spieth. “I was not feeling great after Wednesday, and then after (Thursday) being behind the 8-ball. But to come today and shoot a solid round when I needed to, and to have my putter working when I knew I needed it, gives me a lot of confidence.’’

Next week’s British is at storied St. Andrews, in Scotland – a layout much different than TPC Deere Run.

“I’m excited to go next week just because I love St. Andrews, and I love the town,’’ said Spieth. “It’s going to be an exciting atmosphere, and it may be good for me to have a limited amount of time there just to get some feels. I’ll be able to adjust to the speed and the conditions there. I’ll be able to do that in a couple days.’’

Spieth wasn’t feeling so confident after standing even par for the tournament four holes into Friday’s second round. A two-foot birdie putt put him in red numbers and a 241-yard second shot to a par-5 that set up an eagle was the highlight of his round. He played his last 14 holes in 7-under and, with seven holes left in that stretch, he started to relax.

“Then the cut line was out of my head, and it was `How can we move up the board a little more?’’’ he said.

The shot that set up his eagle at the No. 2 hole (Spieth played the back nine first) may have far-reaching implications. He used a driving iron, while in past years he would have used a hybrid.

“I’ve got this driving-iron I’m using in preparation for St. Andrews,’’ he said. “I want to get some swings with this club. I had a great number there just to launch it up the right side of the green. Obviously I was lucky to coast it the perfect distance and capitalize.’’

Spieth attributed his slow start here to rust. Wednesday’s pro-am was his first 18-hole round in nearly three weeks. During that stretch he went a week without touching a club, but now the vacation is very much over. His bid for the third leg of golf’s Grand Slam will be the talk of the entire sports world after he boards the flight to Europe from the Quad Cities Airport after Sunday’s final round of the JDC.

“I should have gotten out on the golf course a little more than hitting balls on the range,’’ Spieth said before his hot round on Friday. “I’m just looking to get a little better each day.’’

There are some similarities between the front-running Thomas, who also led after Day 1, and Spieth. Both have had sponsor exemptions to get into the JDC (Spieth in 2012 and Thomas in 2013 — and they were teammates on a U.S. junior team that competed in France in their high school years. Then Spieth went, briefly, to Texas and Thomas to Alabama.

“I’d say he got the best of me in amateur golf. I got the best of him in college golf. And so far, he’s got me beat pretty handily in professional golf,’’ said Thomas. Spieth already has accumulated $16 million in PGA Tour winnings in less than three seasons, with nearly $7.9 million coming in the first six months of 2015. Thomas has $1.6 million in seven tournaments spread of the last two years.

“As for a rivalry with Jordan, it’s nothing right now,’’ said Thomas. “I have a lot of to do get to his level. I’m working to get there.’’