Phil Mickelson was among the casualties as a plethora of big names missed the cut at the Farmers Insurance Open on Friday.
The American floundered on the so-called easier north course, completing his round with three straight bogies to finish at one-over-par.
World number two and defending champion Jason Day was another who is heading home early, as is Rickie Fowler.
At the other end of the leaderboard, K.J. Choi is on target for a first PGA Tour win in five years after a round of 67 on the north course gave him a share of the lead with Gary Woodland, who also fired a 67, but on the south course.
Behind them Dustin Johnson is a shot back on eight-under, with joint overnight leader Scott Brown a further shot back.
Andrew Loupe, who shared the overnight lead with Brown, had a disastrous day, shooting a 75 on the south course to leave him six strokes behind the pace.
Leaderboard: -9 Woodland, Choi, -8 D Johnson, -7 Laird, Brown, Horschel, -6 Jacobson, Streelman, -6 Kim, Campbell, Holmes, Huh, Oppenheim
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