From Arnold Palmer's five tournament wins to David Duval's iconic final-round 59 to come from behind and win the 1999 event, The American Express has seen history time and time again.

Now next to Palmer and Duval comes 20-year-old amateur Nick Dunlap.

Looking for most of the day like the magic that had vaulted him to a three-shot lead entering the final round had evaporated, the University of Alabama sophomore Dunlap grinded down the stretch for an historic one-shot victory.

Dunlap becomes the first amateur to win a PGA Tour event since Phil Mickelson in 1991. He set a tournament record by finishing 29-under par.

"It's definitely got a good ring to it," Dunlap said of being a PGA Tour winner. "I will say that. It's everything that I dreamed of and just to have a chance on the last hole to win a PGA Tour event is really special."

As Dunlap played his final nine holes in 2-under par, tour veteran Sam Burns faltered with tee shots into the water on the final two holes Sunday at the PGA West Stadium Course. Burns lost the lead with consecutive double bogeys and finished four shots back in a tie for sixth place.

Dunlap's par and Burns' double bogey on the rock-ringed par-3 17th were enough to give Dunlap the lead after Burns had played steady, consistent golf throughout the day. But Dunlap still needed to scramble for a par on the final hole to stay one shot ahead of Christiaan Bezuidenhout, who played the final four holes in 3-under for a 65. That put Bezuidenhout at 28 under, one shot behind in second place to Dunlap, who managed an up and down on the 18th hole including a five-foot par putt.

"Whether I had made that or missed that, if you would have told me that, you know, come Wednesday night I would have a putt to win this golf tournament, I wouldn't believe you," Dunlap said.

While Dunlap said he did feel the nerves of the moment, he had a big helper beside him in caddie Hunter Hamrick, a former assistant coach at the University of Alabama.

"He was so calm all day, his attitude never changed," Dunlap said. "Just kind of, his last thing is, like, man, this is inside left, you made a million of these putts before, it's just another one."

After opening rounds of 64, 65 and the magical 60, Dunlap said he wasn't sure what to expect from the fourth round.

"Everybody's got doubts. I probably had a thousand different scenarios in my head of how today was going to go, and it went nothing like I expected," Dunlap said. "I think that was the cool part about it. That's golf."

Dunlap's 29-under 259 total is the tournament record since the event switched to a 72-hole format in 2012.

Dunlap's win will resonate at The American Express and across the PGA Tour. Dunlap matches Mickelson's 1991 victory in the Northern Telecom Open in Tucson, when Mickelson was 20 years old. Dunlap, also 20 and the reigning U.S. Amateur champion just as Mickelson was 33 years ago, becomes the youngest winner on the PGA Tour since 19-year-old Jordan Spieth won the 2013 John Deere Classic.

While Dunlap walks away with no prize money, with Bezuidenhout taking home the $1,512,000 first-place check, it is Dunlap who creates history that won't soon be forgotten in the desert or on the PGA Tour.

Dunlap is the first player to win after a sponsor’s exemption since Martin Laird at the 2021 Shriners Hospital event in Las Vegas. In only his fourth professional start, Dunlap made the cut for the first time. He remains only the second player to win the U.S. Junior Amateur and the U.S. Amateur, along with Tiger Woods.

"It's amazing. Actually, I heard his name last year when he won the U.S. Amateur," Bezuidenhout said. "Yeah, he's obviously a hell of a player and congrats to him and hopefully he can be out on the PGA Tour soon, and we all can get to play with him."

Dunlap's play Sunday was not as stellar as it had been the first three days. Having made only one bogey in the first 54 holes, Dunlap double bogeyed the par-4 seventh with a tee shot in a lake and watched Burns make birdie to tie for the lead.

Burns took the lead alone with a birdie on the par-5 11th just as Dunlap was starting to miss a series of short putts for birdies. Dunlap finally caught Burns with a birdie on the par-5 16th, setting up Burns' collapse in the final two holes.

"Hitting my ball in the water on 7, it tested everything I had. I missed a couple putts that I thought I was going to make," Dunlap said. "And just kind of like my sports psychologist, Bhrett McCabe, I went over a scenario for today probably a million times and it's never going to go how you plan, and it didn't. I'm so happy to be standing here."

A flurry of players were still chasing Dunlap and Burns, including Kevin Yu, who tied for the lead at 28 under but bogeyed the 18th hole to finish at 27 under with a final-round 63. Xander Schauffele and Justin Thomas also finished at 27 under to tie for third, with Thomas struggling at times on the way to a 68 and Schauffele just running out of holes in his 65.

"I knew I had to shoot a low weekend, and I was able to," Schauffele said. "I was too far behind after that round of 3-under at Nicklaus Tournament. In a shootout like this, you can't afford to shoot 3-under in any round."