Tony Finau is part of a three-way tie for the lead heading into the final round of The American Express.
The American, whose only previous PGA Tour win came at the Puerto Rico Open in 2016, fired a five-under 67 in the third round in California on Saturday.
Finau was four under through 12 holes in his round before finding water and making a double bogey at the par-three 13th.
But he responded in style, reeling off three straight birdies to get to 15 under – which sees him share the lead with Max Homa (65) and Kim Si-woo (67).
Finau has eight top-10 finishes at majors, but on Sunday will bid to end his wait for a second PGA Tour victory.
Homa, meanwhile, had a double bogey after finding water on the seventh, while Kim went through bogey-free on the PGA West Stadium Course, which hosted the third round.
Richy Werenski (65) is a shot back of the leading trio, while Russell Knox (64), Brian Harman (67) and Emiliano Grillo (68) are at 13 under.
Cameron Davis (66), Rory Sabbatini (67), Chase Seiffert (65), Francesco Molinari (69) and Doug Ghim (69) are tied for eighth.
Molinari, the 2018 Open Championship winner, is playing for the first time since last year's Masters, having missed five cuts in seven events in 2020.
Overnight leader Im Sung-jae slipped back to a tie for 20th after finding the water three times during his round, including twice at the ninth.