Phil Mickelson is the clubhouse leader following the first day of the Northern Trust Open in Pacific Palisades.
Play was suspended due to darkness before the entire field had managed to complete their first rounds but with only a handful of players still on course it was Mickelson would topped the leaderboard.
A winner at Pebble Beach last weekend, Mickelson carded a five-under-par 66 to put him one shot clear of JB Holmes and Hunter Mahan, with Jonathan Byrd and Carl Pettersson a further shot back.
Gusting winds made things tricky for the field but Mickelson coped brilliantly as he recorded six birdies and a lone bogey, which came at the par-three 16th, to leave him in a commanding position going into Friday.
"It feels really good to get that one extra shot because I felt like I left one or two out on 16, 17, and you hate to have such a good round and let a few slide late," Mickelson told www.pgatour.com.
"It was a challenging day today because Riviera doesn't give you great opportunities to run balls onto the green.
"Fortunately the greens were somewhat receptive, and that's why I think the scores weren't extremely high. A lot of them were right around par."
Four consecutive birdies from the fifth, his 14th hole, saw Mahan surge up the leaderboard and he was delighted to finish just one stroke off the lead.
"I hit it good all day, with just a couple loose swings. Other than that, it was very solid from tee to green," Mahan said. "I put myself in good position all day to make putts.
"The last seven holes the wind started to die down progressively, and by the end, it couldn't be playing any nicer or any better, so I was excited to come make some birdies late."
Sergio Garcia is among a group of six players on two-under, while world number one Luke Donald is one-under alongside the likes of Fred Couples, Bubba Watson, and Justin Rose.
Three-time major winner Padraig Harrington is one of the 30 players who will have to return to the California venue to complete his first round. The Dubliner is currently one-over with two holes to play.