California :Masters champion Phil Mickelson and US compatriot Bill Haas shared the third-round lead at Torrey Pines on Saturday as Tiger Woods floundered on a course he has long dominated.
Mickelson, who claimed the most recent of his three Torrey Pines victories in 2001, fired a four-under 68 for a 54-hole total of 12-under 204.
It proved good enough for a share of the lead when overnight leader Haas bogeyed the par-five 18th to complete a one-under 71.
They were one shot in front of Americans Hunter Mahan and Bubba Watson, who both eagled the final hole to card 69s and jump up the leaderboard on 205.
They were one stroke in front of Anthony Kim, who posted a 71 for 206, with Venezuelan Jhonattan Vegas a further shot back on 207 after his third straight 69.
Woods, meanwhile, was nowhere.
On a balmy day that saw as many as five players sharing the lead on 10-under in the early going, he never challenged en route to a two-over 74 that left him eight adrift.
The former world number one, seeking a first tournament title since the Australian Masters in 2009, started the day five off the lead and bogeyed three of his first five holes.
He managed to regain some ground with birdies at the front nine's two par-fives, but couldn't muster a birdie coming in to counter one more bogey at the par-four 15th.
"I did not play well at all today," Woods said. "It was a struggle all day. I finally found something at 16, but 15 holes already had gone by, so that was plenty frustrating."
Mickelson, who once felt right at home at Torrey Pines, was delighted to find himself in contention here again.
"I just love playing well in this tournament and I've missed it," said Mickelson, a Southern Californian who grew up playing Torrey Pines. "I've missed being in contention and having opportunities to win here."
To give himself the opportunity, Mickelson reined in his usual aggressiveness and while he said it might be "boring" he believed his conservative approach "has led me to be on top of the leaderboard."
"I'm not taking on the risk," said Mickelson, who had five birdies and one bogey in a round that was tied for lowest of the day. "I'm just playing it much more conservative because the reward isn't there."
Haas, the son of former US PGA Tour professional Jay Haas, won twice in 2010 and lost a playoff last Sunday to just miss retaining his Bob Hope Classic title.
He tussled with Mickelson for the lead over much of the back nine, edging ahead two strokes when he drained a 25-foot birdie putt at 15 that moved Hass to 13-under.
Mickelson birdied 16 to get to 12-under, and Haas missed a four-footer to save par at the last to share the lead.
"I saw my name up there most of the day and was able to hang in there and hold the lead for some of the back nine there," Haas said. "I hit a lot of quality shots on the back nine...
"Disappointed with the six on the last, but in a decent position for tomorrow," added Haas, who has two top-10 finishes in as many starts this season.
Vegas, who emerged from the playoff victorious at the Bob Hope last week, capped his round with a birdie at the final hole.
The engaging South American said he enjoyed playing in a group with Woods for the first time in his career.
"I felt comfortable playing with him," Vegas said. "And the crowd was crazy, but it was fun. I enjoyed it."