Jon Rahm's phenomenal front nine earned him a share of the lead with Davis Thompson after the third round of The American Express in California on Saturday.
World number four Rahm shot 30 in his first nine holes on the Stadium Course at La Quinta Country Club, including four birdies and an eagle on the fifth to claim the lead by three strokes from Thompson, who had gone into the third day ahead by two.
Rahm launched an aggressive second shot on the par-five fifth, setting up his eagle putt from the edge of the green.
The Spaniard cooled off after another birdie on the 12th to finish the day with a seven-under-par 65, having carded back-to-back 64s on the opening two days.
Thompson shot a five-under-par 67 on the Stadium Course, making an up-and-down birdie on the 16th hole to re-claim a share of the lead.
Rahm and Thompson are joint top on 23-under overall, four strokes ahead of J.T. Poston and Christiaan Bezuidenhout.
Bezuidenhout enjoyed a scintillating 10-under round on the Nicklaus Tournament Course to surge up the leaderboard, making six birdies on his back nine.
But the round of the day went to Dylan Wu, whose 11-under-par 61 matched Will Zalatoris' Nicklaus Tournament Course record.
The American had a run of six straight birdies on his front nine and would have broken the course record if not for a par on the 18th.
Wu, at 17-under, is part of a six-player group that includes world number two Scottie Scheffler.