Brooks Koepka will take a two-shot lead into the final round of the Frys.com Open in California after he shot a four-under round of 67 to double his overnight lead.
The 23-year-old, playing in his first PGA Tour event excluding majors, mixed six birdies with two bogeys to go 15 under overall, two clear of George McNeill and Jason Kokrak.
Koepka is chasing not only his first title on the Tour but also the win that would earn him full Tour membership.
Although relatively unknown in the States, he has done well on the other side of the Atlantic, winning a clutch of second-tier Challenge Tour events to earn his place on the full European Tour.
And he showed that good experience with a solid third round, carding three birdies and a bogey on his front nine, then doing likewise on the way back - including birdies on the final two holes.
That was enough to put him two clear of Kokrak and McNeill, who had a day to remember as he equalled the CordeValle course record with a nine-under 62, mixing 10 birdies with a single bogey.
"It was a lot of fun," McNeill told pgatour.com. "Sixty-two, I don't know how it could ever not be fun.
"I figured out something on the range last night and my swing was much more comfortable today. I felt free so I could go ahead and aim at some flags. I pulled it off and made some putts."
One shot back at 12 under was Jimmy Walker, who also carded a 62, tying a record he already jointly held.
Alongside Walker were Vijay Singh and Robert Garrigus, while Japan's Ryo Ishikawa led a group of five on 10 under.