Jason Dufner goes into the third round of the CareerBuilder Challenge with a one-stroke lead after a strong performance on the PGA West's Stadium Course on Friday.
The American shot a second-round 7-under 65 after parring the final four holes in La Quinta, California.
Dufner (15 under) is one stroke ahead of second-place Jamie Lovemark (14 under), after the 27-year-old posted a 65 on the Tournament Course.
Reigning champion Bill Haas was three strokes behind the lead, alongside Jason Gore, Anirban Lahiri, Andrew Loupe and Adam Hadwin in a tie for third.
Haas shot 66, Gore 64, and Lahiri 68 at the Nicklaus Course, while Loupe had a 66 on the Stadium Course, and Hadwin a 66 at La Quinta.
Lahiri was tied for the lead after the first round but could not back up his opening day heroics.
Two-time winner Phil Mickelson (11 under) shot a 65 on the Nicklaus Course and sits tied for eighth place.
Meanwhile, amateur Jake Pumphrey scored a hole-in-one at the par-3 13th hole of the Stadium Course.