Tiger Woods finished the first round of the Genesis Open six shots off the lead after returning to the Riviera Country Club for the first time in 12 years.
The former world number one started with a birdie at the 10th after a neat wedge approach and well-judged putt, but dropped three shots over the next two holes.
He pulled shots back at 13 and 17, either side of a bogey at 15, and a birdie at the first was followed by bogey at the fifth.
A bogey-birdie-par finish meant a score of one over par and a steady start to the event in California.
The former world number one was playing with Rory McIlroy and Justin Thomas and all three birdied their opener, McIlroy holing from a bunker.
Thomas gave the shot back at the 13th but picked up another at 17, when he initially appeared disgusted with his over-hit putt before stopping in surprise when it clattered the back of the hole and dropped.
He recovered from two dropped shots with two birdies in his last three holes to finish two under.
McIlroy carded an even-par 71 in the opening round after failing to make the cut at last week's AT&T Pebble Beach Pro-Am.
He dropped shots at 11, 12 and 17 but eagled the first hole, having learned from Thomas' under-hit effort.
He parred his way in from there but was left in the shadows by fellow Northern Irishman Graeme McDowell, who matched Thomas' two-under-par round after three birdies and just a solitary bogey at the 13th.
Day one went to Patrick Cantlay and Tony Finau, who share the lead after carding rounds of five-under 66.
Finau had four birdies in his first five holes, making just one bogey on the par-three fourth hole.
Cantlay, returning after a long-term injury, himself shot a bogey on the fourth, but recovered with six birdies in total, including a 31-foot putt on the par-four seventh hole.
Bubba Watson, who carded a round of three-under 68, hit the shot of the day after nearly making an ace from a 181-yard tee shot on the par-three sixth hole.
Round one was later suspended due to darkness with 13 players yet to finish.