South African Rory Sabbatini moved four shots clear in the Nissan Open second round on Friday, while Tiger Woods and Ernie Els scraped past the halfway cut.
Sabbatini notched five birdies in a row on his way to a sparkling six-under-par 65 on a clear, chilly morning at Riviera Country Club, finishing at 10-under 132.
French Ryder Cup player Thomas Levet fired a second successive 68 for a share of second place at six under with American Craig Barlow, who carded a 69.
Another South African, Trevor Immelman, was a further stroke back in a tie for fourth, a hole-in-one at the 165-yard 16th helping him to a 70.
Much of the interest, however, focused on whether the two biggest names in the 144-strong field would be around for the weekend.
World number one Woods, who battled flu on his way to an opening 69, bogeyed his last two holes for a 74 to finish right on the cutline of one-over 143. Eighty-three players qualified for the weekend.
Fourth-ranked Els, who has not missed a PGA Tour cut since the 2004 Bay Hill Invitational, ended up one shot better at level par after carding an erratic 72.
Also suffering from a cold, Els dropped three shots in his first three holes before recovering with birdies at the 10th, 11th and par-five 17th.
Woods, who won his first two tournaments of the year via playoffs, did not have an umbrella in his bag when a rainstorm blew across the course midway through the afternoon.
"It's been a while since I got caught out like that," he told reporters. "I'm pretty cold right now. It was a little wet and a little cold coming in.
"I was just trying to hit the ball solid and give myself some putts at it. I drove it great today but I hit my irons terrible. And I had a hard time on the greens."
Els, the 1999 champion, was disappointed with his performance.
"I had no energy this morning and it was a little ugly out there. My iron play let me down a little bit. It was the early start, I guess," said the South African, who has made 24 consecutive cuts on the PGA Tour.
"I'm not trying to keep the cut streak alive. I'm simply trying to get back into the tournament.
"If you make it to the weekend, you get half a chance."
Sabbatini, playing his sixth PGA Tour event in seven weeks, has been in prime form with this season with five top-20 finishes, included two runner-up places.
"I've been playing nicely, managing to get the ball close to the hole and making the most of my opportunities," said the Texas-based professional.
"You have to be very precise out here at Riviera because, for the most part, the greens aren't that big here.
"Coming into this week, my body felt pretty fatigued but I've managed to find the energy to maintain my concentration out there and stay focused," he added.
Another player to shine in the morning was American Brian Gay, who registered the first albatross (double-eagle) of the season by holing out with a five-iron from 198 yards for a two at the par-five first.
He finished with a 67 and a share of 11th place at four under.