Los Angeles - Tiger Woods, seeking an unprecedented 83rd career PGA Tour victory, fired a three-under par 69 that left him three off the first-round lead shared by Sebastian Cappelen and Keegan Bradley at Torrey Pines.
At the famed tract north of San Diego, where the 44-year-old American has previously captured eight titles, Woods closed with a five-foot birdie putt on the ninth hole of Torrey Pines' North Course, with golfers also competing on the harder-playing South Course.
"Overall, I'm pleased to shoot in the 60s. The course was gettable today," Woods said. "I felt like I hit the ball well.
"I'm very pleased to get something in the red and get over to south tomorrow."
Sixth-ranked Woods matched US legend Sam Snead for the all-time US PGA title record on 82 by winning last October's Zozo Championship in Japan and this is his first opportunity to claim sole possession of the mark.
Woods, who won his 15th major title at the Masters last April, broke 70 in an opening round at Torrey Pines for the first time since 2013, when he captured his most recent Farmers Insurance Open victory on his way to five titles that year.
"I definitely was feeling it," Woods said of the adrenaline competition brings. "I missed the competition.
"I tried to keep everything as calm as I possibly could. I didn't do well at the start with a bogey. I fought back. I take a lot of positives to the South Course."
Danish rookie Cappelen made eight birdies and two bogeys on the South Course to seize his share of the lead.
He was joined on six-under by 2011 PGA Championship winner Keegan Bradley, who had an eagle and four birdies on the North Course.
Rory McIlroy, who can regain the world number one ranking with a victory this week, headlined an eight-strong group sharing third place on 67 that also included two-time Masters champion Bubba Watson, South Korean An Byeong-hun, China's Zhang Xinjun and Americans Kevin Tway, Joel Dahmen and Matthew NeSmith.
Spain's Jon Rahm and Australians Marc Leishman and Cameron Percy were in another big group on 68.
Rahm played alongside Woods and 22-year-old American Collin Morikawa - who wasn't born when Woods made his pro debut.
McIlroy was back in action after a six-week break.
"I drove the ball well for the most part," he said. "A little rusty around the greens but with a little more practice I'll feel a little more composed as the week goes on.
"I feel like I need to improve every day and if I do that I'll be right in contention."
Woods, who began on the north's back nine, found a bunker at the par-4 11th and made bogey but answered with a birdie at the par-4 13th. He struck again for a birdie at the par-5 17th but took a bogey at 18 to make the turn level.
Woods reached 2-under on his second nine by sinking a six-foot birdie putt at the first hole and tapping in for birdie at the par-5 fifth after missing left on a 20-foot eagle putt.
At the par-3 eighth, Woods found a greenside bunker but blasted out and sank his par putt, setting the stage for his closing birdie.
"That was nice to keep the round going," Woods said of his penultimate-hole par save.
Leading first-round scores on Thursday in the US PGA Tour Farmers Insurance Open at Torrey Pines in La Jolla, California (USA unless noted, par-72):
66 - Sebastian Cappelen (DEN), Keegan Bradley
67 - An Byeong-hun (KOR), Joel Dahmen, Kevin Tway, Rory McIlroy (NIR), Zhang Xinjun (CHN), Matthew NeSmith, Im Sung-jae (KOR), Bubba Watson
68 - Cameron Tringale, Billy Horschel, Stewart Cink, Jon Rahm (ESP), Cameron Percy (AUS), Marc Leishman (AUS), JB Holmes, Brandon Wu, Dominic Bozzelli, Vincent Whaley
69 - Wyndham Clark, Jhonattan Vegas (VEN), Charley Hoffman, Patric Reed, Patton Kizzire, Brandt Snedeker, Russell Knox (SCO), Tiger Woods, KK Limbhasut (THA), Jason Kokrak, Kang Sung (KOR), Pat Perez, Rhein Gibson