Martin Laird of Scotland fired a four-under-par 67 to claim a share of the lead after the opening round of the Northern Trust Open in California.
Laird finished with six birdies and two bogeys to form part of a nine-man group at the top of a congested leaderboard at Riviera Country Club.
American quartet JB Holmes, Bill Haas, Spencer Levin and Ben Martin and Australian trio John Senden, Robert Allenby and Aaron Baddeley also ended the day on four-under, along with Sweden's Carl Pettersson, when play was suspended due to darkness with 14 players still out on the course.
American former Ryder Cup captain Corey Pavin had looked set to eclipse the rest of the field and claim sole possession of the lead, but three bogeys in his final four holes saw him drop back from five-under to two-under.
Ireland's Padraig Harrington and English pair Brian Davis and Luke Donald were amongst five players to finish just one back of the clubhouse lead on three-under, alongside Vijay Singh and Fred Couples.
Donald produced a late surge, picking up three birdies in his final five holes to move himself into contention.
American Peter Tomasulo was also on three-under with one hole of his opening round still to play.
Meanwhile, Justin Rose and South Africa's two-time former US Open champion Retief Goosen were among 10 players on two-under.
Pre-tournament favourite Phil Mickelson had to settle for a level-par 71 after an up-and-down round that featured four birdies and four bogeys.
"I got off to a good start," said Mickelson, who birdied his first two holes, the 10th and 11th.
"I was a couple under, thought it was going to be a great day but gave a lot of shots back, made too many bogeys.
"Even-par, I'll have a good chance tomorrow morning to get out and try to go low.
"This afternoon it was tough to make some putts. Even though there were some low scores, I struggled getting the ball to go in."
Dustin Johnson was handed a two-shot penalty even before he had played a shot after arriving on the first tee with just 10 seconds to spare.
The American said his caddy had got his Wednesday pro-am tee-time mixed up with the opening round, meaning his par-five at the opening hole became a seven.
And Bubba Watson will take no further part in the tournament after he shot a five-over-par 76.
The Ryder Cup star is struggling with a stomach muscle injury and said he is 'not in the right place' to concentrate on golf.