Norway's Viktor Hovland sank a 10-foot birdie putt on the last hole Sunday to win the Mayakoba Classic by one stroke over American Aaron Wise.
It was the second PGA Tour title for the 23-year-old from Oslo, who also rolled in a birdie on the 72nd hole to win February's Puerto Rico Open.
"I don't feel comfortable in these situations at all. I was shaking there at the end," Hovland said. "I knew I had to make a birdie on 18 and it just went in."
Hovland, ranked 25th, fired a six-under par 65 in the final round to complete 72 holes at Playa del Carmen, Mexico, on 20-under par 264.
Wise, who fired a closing 63, was second on 265, with fellow Americans Tom Hoge and Adam Long sharing third on 267 and compatriots Lucas Glover, Harris English and Billy Horschel another stroke adrift.
"I hit every shot basically as well as I could hit it," Wise said. "Felt really comfortable and was able to give it a run. I just couldn't get one to drop on that back side."
Hovland, who matched a PGA Tour career low with a 63 on Saturday, birdied four of the first six holes Sunday and jumped into the hunt.
After making his lone bogey at the par-4 12th, Hovland answered with birdies at the par-5 13th and par-4 14th to share the lead with Wise, who birdied 13, 14 and the par-3 15th.
Hovland's five-foot birdie putt at 15 lipped out, leaving him still deadlocked with Wise, and he stayed that way at the 16th despite finding a bunker on his approach, blasting out and holing a tense five-foot par putt.
"I thought I had lost it after the second shot on 16, but made an awesome putt there," Hovland said. "My golf was very steady today. It could have been a lot worse."
Wise, who was born in South Africa, had a chance to seize the lead alone at 18 but missed a seven-foot downhill birdie putt, setting the stage for Hovland's dramatic winning moment.
Wise won his only PGA Tour title at the 2018 Byron Nelson tournament while Long's only top-level win was at the 2019 Desert Classic.
Argentina's world number 171 Emiliano Grillo, who began the day with a one-stroke edge for his first PGA Tour 54-hole lead, fired a closing 72 to share eighth on 269.
World number three Justin Thomas, the 2017 PGA Championship winner, fired a 69 to share 12th on 270.