World Number 75 Kim Si-woo produced a faultless round to become the youngest champion at the Players Championship.
Kim, 21, shot a three-under-par 69 on the final day at Sawgrass to finish on 10 under and replace Adam Scott as the youngest winner of the Championship.
England’s Ian Poulter was tied for the lead at one stage but finished three shots behind in a tie for second with Louis Oosthuizen after a 71.
Rafa Cabrera Bello and Kyle Stanley finished tied for fourth on six under.
After his victory in the Wyndham Championship last year, Kim is the fourth player in the last 25 years to win twice on the PGA Tour before clocking the age of 22, following in the footsteps of legends such as Tiger Woods, Sergio Garcia and Jordan Spieth.
Kim started the final round two shots behind overnight leaders JB Holmes and Stanley while Poulter, chasing a first victory since 2012 and a maiden strokeplay success in the United States, was three behind.
But with Holmes and Stanley failing to sustain their challenges in blustery conditions, Kim and Poulter both knocked in early birdies to share the lead.
Birdies on the seventh and ninth made the South Korean the first player to reach 10 under par this week and gave him a two-shot lead.
Poulter reduced the deficit to one but then, having gone 39 consecutive holes without a bogey, dropped a shot on the 12th.
The 41-year-old tried to put Kim under pressure but the putts would not drop and the leader remained agonisingly out of touch.
Kim saved par from tricky positions on both the 10th and 11th and safely negotiated the challenge of the water at the 17th with a bold tee shot and two composed putts.
After Poulter dropped a shot on the 18th, Kim went on to secure the biggest win of his fledging career with another par.
It has still been a week to remember for Poulter, who three weeks ago thought he had lost his PGA Tour card after falling to 197th in the world rankings.
That was until fellow professional Brian Gay alerted officials to a mistake in the points structure used for players competing on major medical extensions.
The former world number five, who only played 13 tournaments in 2016 because of a foot injury will climb back into the top 100 in the new rankings.
“From being in a position a couple of weeks ago where I wasn’t here to finish tied second, it’s a good week,” Poulter told Sky Sports after his best finish since November 2014.
“It has been a tough 18 months. Today I felt like a couple of putts slid by, but I played well under pressure, barring that horrible second shot on the last.
“I’ve enjoyed it and hopefully this is just a stepping stone to pressing on for the rest of this year.”