Los Angeles - Jason Dufner, seeking a first US PGA Tour title since his major triumph at the 2013 PGA Championship, fired a seven-under par 65 on Friday to take a one-shot lead in the CareerBuilder Challenge.
Dufner had eight birdies in his round on the TPC Stadium Course at PGA West in La Quinta, in the southern California desert, the toughest of three par-72 layouts in use over the first three days of the $5.8 million tournament.
His 36-hole total of 15-under par 129 put him one stroke in front of Jamie Lovemark, who carded a seven-under 65 on the Nicklaus Tournament Course for 130.
Dufner got off to a blazing start on the Stadium Course, back in the tournament rotation for the first time since 1987, with six birdies in the first nine holes.
After a bogey at 10 he birdied two of the next three and parred the last four to equal the best score of the week on that course.
"It's a difficult golf course," Dufner said.
"There's a little bit of room to play off the tee, but if you get off the path a little bit, you can get into some trouble. ... It's definitely the most difficult of the courses we have played here."
Lovemark teed off on 10 and enjoyed a round highlighted by an eagle at the par-four first, where he holed a shot from 105 yards out.
"Got a little tired coming down the stretch," admitted Lovemark, who also had six birdie and a bogey.
"There's some long rounds out here."
Defending champion Bill Haas, a two-time winner of the event, carded a second straight 66 and was among a group sharing third on 132.
He was joined by overnight co-leader Anirban Lahiri of India, who shot 68, Canada's Adam Hadwin (66), Jason Gore (64) and Andrew Loupe (66).
Five-time major champion Phil Mickelson headlined a group sharing eighth on 133 after a 65 on the Nicklaus Tournament Course.
He was joined at 11-under by Argentina's Angel Cabrera, Michael Thompson, Brian Harman, Brendan Steele, Ryan Palmer and John Huh -- who carded an eight-under 64 on the Tournament Course.
Mickelson, teeing it up for the first time since September, said he's still not 100 percent confident in his game.
But he still thought he had a shot at adding a third title to the ones he captured here in 2002 and 2004.
"I'm probably a week away, if I'm being honest," Mickelson said. "But I've also won with a lot less game than I have right now."
129 - Jason Dufner 64-65
130 - Jamie Lovemark 65-65
132 - Adam Hadwin (CAN) 66-66, Jason Gore 68-64, Andrew Loupe 66-66, Anirban Lahiri (IND) 64-68, Bill Haas 66-66
133 - Angel Cabrera (ARG) 67-66, Phil Mickelson 68-65, Michael Thompson 66-67, Brian Harman 67-66, Brendan Steele 68-65, Ryan Palmer 67-66, John Huh 69-64
134 - Francesco Molinari (ITA) 67-67, Matt Kuchar 67-67, Jerry Kelly 64-70, Colt Knost 65-69