Ryder Cup rookie Ben Griffin maintained his lead heading into the final round of the Procore Championship with Scottie Scheffler among those giving chase.
Griffin carded a two-under-par 70 to move to 16-under-par, holding off a pair of world number ones at the Silverado Resort, Napa.
Top-ranked amateur Jackson Koivun sits just one shot back after a third-round 68, while world number one Scheffler is a further stroke behind after an eight-under-par 64 which included a double bogey on the 14th.
Seamus Power is sitting in a share of 25th following a two-under 70 on Saturday to move to six under, ten shots off the lead.
Griffin, who started Saturday with a three-shot lead, stayed ahead but saw his lead shrink when he made a bogey at the hole after hitting a chip too thin and sending it past the green.
After his mishap on the 14th, Scheffler rallied with three of his 10 birdies over the closing four holes.
"If I go out and play good consistent golf, I'm going to start moving my way up the leaderboard and that was the goal going into today," Scheffler said.
"Hit a lot of greens, holed some putts."
