South Korea's Si Woo Kim produced a nerveless display to become the youngest ever victor of the Players Championship as Ian Poulter had to settle for a share of second place.
Kim's second PGA Tour victory earned him US$1.89 million (US$1=W1,123).
Poulter, who tied Oosthuizen for second, trailed by two shots for nearly the entire back nine. Not Kim. Once he gained an upper hand on the field, the seventh global Players champion in the last 10 years shut the door for good.
"I feel like I'm still dreaming that I won this championship", Kim said after claiming the victory.
It offers exemptions to athletes who win a medal of any colour at the Olympics or gold at the Asian Games but unfortunately for Kim, winning the PGA Tour's flagship event does not bring an exemption.
European PGA: Matt Wallace completed an unlikely wire-to-wire victory in the Open de Portugal to earn a European Tour card.
Poulter had slipped from a career-high of fifth in the world to 197th and just three weeks ago had seemingly lost his PGA Tour card until fellow professional Brian Gay alerted officials to a discrepancy in the points structure used for players competing on major medical extensions.
Si Woo Kim, of South Korea, chips onto the third green during the final round of The Players Championship golf tournament Sunday, May 14, 2017, in Ponte Vedra Beach, Fla. Other than Kim, Wang Jeung-hun and An Byeong-hun are listed at 57th and 58th in the world ranking as of Sunday.
There was no indication coming into The Players that Kim would be a factor.More news: Senate intelligence committee subpoenas Michael Flynn
More news: Rafael Nadal wins 30th Masters title in Madrid
More news: Trump and Turkey's Erdogan hail ties despite US arming of Kurds
It has been a tough period for the Ryder Cup legend as injury robbed him of a few months of action last season, but he is determined to rediscover his top form.
"The last 18 months have been really miserable but I grew in confidence as the afternoon went on, and now I want to build on it and get back to the top of the game", Poulter told reporters after Sunday's round.
He finished at 5-under 283 to tie for sixth with Scott (70), Brendan Steele (68) and Francesco Molinari (71).
Ian Poulter salutes the crowd after nearly pitching his fourth shot into the hole on the 18th green.
But Choi needed a David Toms three-putt on the first playoff hole to raise his Waterford crystal. McDowell shot a final round of 80 to finish on +9.
"To have two, three weeks ago been in a position where I wasn't playing THE PLAYERS and potentially didn't have a card to play", Poulter said, "and was looking to write nice letters to Jack for Memorial and all of those great tournaments that I'd like to play in - things change pretty quick with good golf, and that's what I've done this week". He followed that with birdie on 17, then holed a long par putt from just off the 18th green.
Spain's Rafa Cabrera Bello made Players history, producing an astonishing final three holes to finish in a tie for fourth with Kyle Stanley.
"As good as he played yesterday, he's obviously gone out there today and played even better", Poulter said.
84 Score of third-round co-leader J.B.