Si Woo Kim birdied two of his final three holes to win the American Express by a single stroke.
The Korean carded a bogey-free eight under par 64 to finish at 23 under at PGA West in La Quinta, California.
The 25-year-old now has three PGA Tour victories, including the 2017 Players Championship.
Kim withdrew from this event last year with a back injury after an opening 87 – a year on he was lifting the trophy.
Starting the day tied for the lead, he had ground to make up in the closing stages after a phenomenal round from Patrick Cantlay.
Cantlay made 11 birdies and seven pars to shoot an incredible course record 61, forcing Kim to make two birdies coming home.
Kim was up to the challenge, making a simple birdie at the 16th after finding the par-5 in two before holing from 19ft at the island-green 17th to essentially seal the win.