J.T. Poston claimed his second PGA Tour win on Sunday, holding on to win the John Deere Classic at TPC Deere Run.

The 29-year-old posted a two-under 69 in the fourth and final round to finish on 21-under for the tournament, three shots clear of Emiliano Grillo and the fast-finishing Christiaan Bezuidenhout, tied for second at 18-under.

As well as qualifying for The Open Championship, Poston becomes the first player since David Frost in 1992 to go wire-to-wire at the John Deere Classic and only the third in the tournament's history along with Scott Hoch, who achieved the feat in 1980.

Poston revealed it was not easy to remove the possibility of that achievement from his mind following his round, but with his last win coming at the 2019 Wyndham Championship, believes it is a boost for his confidence.

"It is hard," he told CBS. "I mean, wire-to-wire, having the lead for that long, it's just hard not to think about it and think about that finish line.

"I tried to stick to the game plan. We got off to a great start and then, kind of started to try and give some back, but I hit a lot of good shots down the stretch.

"I was just trying to breathe. I think there were a lot of nerves, more than the first few days. I was just trying to battle through them and I think, after this week, knowing I can play with those nerves. I can still win, I can still shoot a solid score considering the pressure and trying to win out here."

Poston started strongly, opening the round with consecutive birdies on each of the first three holes, but his momentum was halted with bogeys on the fifth and sixth holes.

His round stabilised on the back nine, however, with a birdie on the par-five 17th effectively securing the tournament.

Poston was able to see off Grillo and Bezuidenhout, who claimed three birdies over the closing five holes, with Christopher Gotterup and Scott Stallings finishing a further stroke back on 17-under.

J.T. Poston holds a three-stroke lead heading into the final round of the John Deere Classic after shooting a four-under 67 on Saturday.

Trying to complete a wire-to-wire victory after tying for second last weekend at the Travelers Championship, Poston sits on 19-under after 54 holes at TPC Deere Run.

The 29-year-old started strongly with three birdies on the front nine, but suffered a blip on the closing nine holes, with a birdie on 14 softening the blow of bogeys on 12 and 15.

He recovered to take momentum into Sunday with an eagle on the par-five 17th, forcing his way past the bunkers on his approach to the green to then one-putt and restore breathing room from the chasing pack.

Despite the solid form coming into this weekend in Silvis, Poston's lone win on the PGA Tour came in 2019, taking out the Wyndham Championship.

He leads a three-way tie for second between Scott Stallings, Denny McCarthy and Emiliano Grillo, who birdied four of the last five holes on Saturday to finish on 16-under.

Out of the top four players on the leaderboard, McCarthy is the lone player not to have won a tournament on the PGA Tour, with Stallings and Grillo's last wins coming in 2014 and 2015 respectively.

Trailing them is Callum Tarren on 15-under, with Bo Hoag and Chris Naegel tied for sixth on 14-under.

Hoag, the world number 524, was Saturday's big mover with a third-round score of eight-under, opening the first four holes with two birdies and an eagle.

He more than compensated for his solitary bogey on 15 with birdies on 14, 16 and 17 to finish with the day's lowest score.

J.T. Poston continued his terrific run of form on Friday to extend his lead to four strokes at the John Deere Classic, sitting at 15 under through 36 holes.

Coming off a second-place finish at the Travelers Championship last week, Poston shot Thursday's round of the day with a 62, and followed it up with a 65. Only six players had better rounds on Friday, with Maverick McNealy the sole 63.

Through two rounds, Poston now has 14 birdies, one bogey and one eagle.

In outright second place is Denny McCarthy, with rounds of 66 and 65, including going bogey-free on his second trip around the course to head into the weekend at 11 under.

The rest of the top-10 has strong international representation, with Austria's Matthias Schwab and Argentina's Emiliano Grillo part of a four-way tie for third place at 10 under, while Taiwan's C.T. Pan, England's Callum Taren and Canada's Michael Gligic are a further shot back in the log-jam at nine under.

South Africa's Christiaan Bezuidenhout and Canada's Adam Svensson are at eight under, America's Charles Howell III is at seven under, while India's Anirban Lahiri and Australia's Cam Davis highlight the large group at six under.

After narrowly missing out on a win at the Travelers Championship last weekend – losing due to a double-bogey on the 72nd hole – Sahith Theegala finished right on the cut-line at three under, highlighting the friendly scoring conditions.

John Huh missed out on the weekend's play by one stroke, Webb Simpson finished one under, and Cameron Champ missed the cut by three shots at even par.

American J.T. Poston played a near-flawless opening round at TPC Deere Run to lead the John Deere Classic by two strokes after Thursday's action.

Poston, who was one career PGA Tour win back at the Wyndham Championship in 2019, is arguably in career-best form at the moment after finishing tied for second in last week's Travelers Championship. He also finished tied for third at the Wells Fargo Championship, and collected another top-10 at RBC Heritage. 

He posted seven birdies, and an eagle on the par-five second hole, in his bogey-free round, finishing with a nine-under 62.

Speaking to the media afterwards, Poston said he can feel himself in a groove.

"I think it's starting to kind of come together and see the results and see the shots, and kind of building that confidence back into my ball striking," he said.

"Hit my irons really well and hitting a lot of fairways, so I'm able to kind of attack some of the pins. Really, just hitting a lot of greens, which is something I haven't done in the first part of the year.

"It's obviously been the secret I guess, so hopefully keep it going."

In outright second place is Canadian Michael Gligic, who also went bogey-free, draining seven birdies for his seven-under 64.

Vaughn Taylor and Christopher Gotterup are tied for third at six under, while the group of Ricky Barnes, Denny McCarthy, Chris Naegel and Dylan Frittelli sit tied for fifth at five under.

A log-jam at four under features Austria's Matthias Schwab, Canada's Adam Svensson and American Scott Stallings, while Australian Cam Davis and Argentina's Emiliano Grillo are one further shot back.

Cameron Champ and India's Anirban Lahiri are at two under, Maverick McNealy and Rory Sabbatini are one under, and Webb Simpson is the pick of the players at even par.

John Deere Classic leader Luke List was delighted to be back out on the course and enjoying his golf after a tough time of things in his personal life.

List's newborn son Harrison was in intensive care after contracting a respiratory virus but is thankfully now home and recovering.

However, it was a difficult few weeks for List, who shot a 63 on Friday tomove a shot clear of joint overnight leader Sebastian Munoz.

"It was tough, but it's been amazing to come back," he said.

"Everyone has been asking and praying and thinking about us, so it's kind of cool.

"It's a big family out here, and it's nice to know that you've got everyone's support when it's not going great."

List's card showed eight birdies as he moved to 13 under for the tournament, one clear of Munoz after the Colombian's 67.

A group of seven players sit on 11 under in a tightly congested leaderboard.