American Patrick Cantlay posted nine birdies in a seven-under 65 to capture the Zozo Championship by one stroke.
The 28-year-old world number 14 began the final day three shots behind leader Justin Thomas but finished on 23 under for his third PGA Tour victory.
Thomas made three birdies in the first six holes but finished with a 69 to share second with Jon Rahm (68).
Rory McIlroy made 29 birdies over the week, his record for a PGA Tour 72-hole event, but was eight back in tied 17th.
In cool, overcast Californian conditions for the final day, Cantlay moved two shots ahead with four birdies in five holes from the 11th, but dropped a shot after inexplicably pulling a wedge into a tree at the par-five 16th.
He parred the final two holes to set the clubhouse target, leaving Rahm needing to hole from 19 feet at the last for a birdie to force a play-off.
It stayed up and the Spaniard was denied a return to the top of the rankings as world number three Thomas, one ahead going into the final round, made a closing birdie to match him at 22 under.
"I put in a lot of work and try to do the right things all the time, so when it all does come together, it's really rewarding because it's all that hard work paying off," said Cantlay.
Tiger Woods, a five-time winner and five-time runner-up at the Sherwood Country Club and defending Zozo champion following his win in Japan last year, finished joint 72nd at one under after a 74, with playing partner Phil Mickelson 76th at three over after a 78.