Three straight bogeys by Phil Mickelson saw him miss the cut at the Farmers Insurance Open at Torrey Pines as American Gary Woodland and South Korea's KJ Choi lead on nine under par.
But at least Mickelson was in good company as defending champion and world number two Jason Day also failed to make it to the weekend's play in California.
Woodland hit a five under par 67 on the South Course and Choi equalled that score on the North Course to lead by one stroke from home player Dustin Johnson.
Woodland had eight birdies and three bogeys and Choi seven birdies and two bogeys.
Woodland told the PGA Tour website: "I drove the ball in the middle of the fairway. Good things are happening when I drive the ball on the fairway.
"I'm confident with the way it is. I'm confident with this golf course. I've played well here the last couple of year so I'm excited about the weekend."
A three-way tie for fourth on seven under par features Scotland's Martin Laird and Americans Scott Brown and Billy Horschel.
Ireland's Paul Dunne is tied for 18th on four under, two shots ahead of fellow countryman Shane Lowry and England's Greg Owen.
With the cut falling at one under England's Justin Rose and Paul Casey were a shot away after finishing their second round on even par along with American Rickie Fowler.
Mickelson's poor late run saw him finish on one over with Day a shot further back. England's Brian Davis finished on three over par and also missed the cut.