A mixed round from Rory McIlroy left him four shots off the lead at the halfway point of the Northern Trust Open in California.
The world number three carded a two-under-par 69 to stand at six under par after two rounds, four off leader Jason Kokrak going into the weekend.
McIlroy might have been hoping for better after striking three birdies in the opening nine holes, but some struggles with his putter on the back nine saw him drop shots at the 10th, 13th and 15th. However, birdies on the two par fives, including the 18th, kept him in contention.
“I played the front nine very well, very solid, at three-under par,” said McIlroy. “The back nine was a little scrappy.
“A bogey from the middle of the fairway at 13 and then to three-putt 15 . . . two unforced errors there. I can’t make those going into the weekend if I want to have a chance to win.”
Pádraig Harrington will also be involved in the weekend action after a one-under 71 left him on one under for the tournament.
American Kokrak gave himself a fine chance of earning a maiden PGA Tour title after an exemplary 64, which saw him fire eight birdies and just one bogey. He came home in five under after a scorching back nine to finish on 10 under.
He his one shot clear of Chez Reavie, who went round in 67, with fellow Americans Dustin Johnson, Troy Merritt and Bubba Watson a shot further back on eight under.
Justin Rose finished with three birdies to propel himself up the leaderboard to five under but it was a bad day for first-round leader Camilo Villegas.
After starting the day on eight under after a scintillating 63 on Thursday, the Colombian needed an extra 11 shots during his second round, which started badly as he made a double bogey at the second hole.
World number one Jordan Spieth enjoyed a better day than his opening round, but still missed the cut. Spieth carded his worst ever opening round with a 79 and he responded with a three-under 68, which included eight birdies, but it was not enough to keep him in the tournament.