Justin Thomas came with Danny Lee via a battle to register a two-shot victory.
While Lee 69 saw the New Zealander maintain second, thomas published a 67 to end the week on 20 under and win the episode for the second time in three decades.
While Tyrrell Hatton finished seven strokes with home favourite Byeong Hun An into tied-sixth three birdies in the last four holes raised Hideki Matsuyama alongside Gary Woodland and Cameron Smith into a share of third.
Other than this bogey on 17, I really feel as if I did what I had to do to win the championship today, Thomas stated. Its very reassuring knowing that I could reach those shots when I had to the entire afternoon once I felt as though that the heat was about the whole moment.
Thomas began at a share of the guide but moved with two birdies in his opening three holes, before a two-shot swing at the fourth watched Lee pickup a shot.
Lee temporarily held the outright advantage with a birdie but Thomas bounced straight back with a birdie at the second, before the pair exchanged gains at the ninth to make it to the turn tied for the lead.
Both players submitted a birdie-four in the 12th and Thomas added another in the 14th to move with the American doubling when Lee overlooked a 10-footer to save par.
After going to bunker as Thomas recovered from a bogey to match the New Zealanders birdie at the final and stable his own PGA Tour name, lee expanded the gap.
Matsuyama posted a seven-under 65 to maneuver alongside Woodland along with Smith on 15 beneath, though end was seen by a finish the week at tied-31st and ensure he will remain in the planets top 50.