Los Angeles - Phil Mickelson fired a six-under par 66, including an eagle and a holed-out bunker shot, and leaped into contention after Friday's second round of the PGA Tour's CareerBuilder Challenge.
The 46-year-old US left-hander, playing his first event since October following two sports hernia surgeries, made six birdies, two bogeys and an eagle to move four strokes back of leader Hudson Swafford, who fired his second consecutive 65 to stand on 14-under 130 after 36 holes.
"I feel like I'm improving quite a lot from when I started (practicing) last Saturday," Mickelson said. "I'm hitting more and more good shots each day and fewer bad ones."
New Zealand's Danny Lee and American Dominic Bozzelli, a US PGA rookie, shared second on 131, one stroke ahead of Americans Brendan Steele and Brian Harman.
Mickelson, who won the tournament in 2002 and 2004, was on 134 alongside England's Greg Owen and Scotsman Martin Laird in a share of sixth at the California desert event, which uses three courses before making a cut after 54 holes.
"It has been a fun few days," Mickelson said. "The courses give you a chance to get away with a few shots. I made a lot more good shots today than I did yesterday."
Mickelson, a three-time Masters champion, has not won since taking his fifth major title, and the 42nd of his career, at the 2013 British Open.
Starting on the back nine of the Nicklaus Tournament course, Mickelson eagled the par-5 11th with a 10-foot putt and birdied 14 before his lone stumbles of the day, bogeys at the 16th and par-3 17th. He found greenside bunkers on each, unable to escape the sand with his second shot at 17.
Mickelson answered by sinking a 10-foot birdie putt at 18 and then holed a stunning bunker shot to birdie the first hole.
Heavy rain hit the course but Mickelson responded by running off three birdies in a row, closing the streak with a 15-foot birdie putt at the sixth.
"It was really hard in these conditions," Mickelson said. "I actually made some birdies in these conditions. The (day's) back nine I played some really good golf."
Swafford, also playing the Nicklaus layout starting on the 10th tee, birdied three of his first five holes, then the 18th and first back to back and the par-5 fourth and seventh holes as well.
"Very solid, very patient," Swafford said. "Hit a lot of good quality iron shots, hit a lot of good putts, gave myself a lot of chances."
World number 204 Swafford, seeking his first PGA victory, also opened on 130 after 36 holes last week in Hawaii on his way to a share of 13th.
"Just really focusing on rhythm with everything I do. It's really kind of coming together," Swafford said.
"I haven't been in bad position off the tee, which is really key, and the putter feels good in my hands."
scores after Friday's second round of the US PGA Career Builder
Challenge played on the La Quinta, Nicklaus Tournament and Stadium
courses at La Quinta, California (USA unless noted):
130 - Hudson Swafford 65-65
131 - Dominic Bozzelli 64-67, Danny Lee (NZL) 67-64
132 - Brendan Steele 68-64, Brian Harman 67-65
134 - Greg Owen (ENG) 67-67, Martin Laird (SCO) 68-66, Phil Mickelson 68-66
135 - Chad Campbell 66-69, Chris Kirk 69-66, Charles Howell 67-68, Harold Varner 65-70
136 - Patton Kizzire 65-71, Paul Casey (ENG) 67-69, Aaron Wise 68-68,
Zac Blair 67-69, Geoff Ogilvy (AUS) 67-69, Bud Cauley 69-67, Sean
O'Hair 67-69, Ricky Werenski 69-67
137 - Jason Dufner 71-66, J.T. Poston 69-68, Luke List 67-70, Grayson
Murray 68-69, Robert Garrigus 68-69, Bryce Molder 69-68, Jon Rahm (ESP)
71-66, David Lingmerth (SWE) 69-68, Seamus Power (IRL) 67-70, Ryan