Darren Clarke was disqualified from the $4.5 million dollar PGA Buick Invitational after signing an incorrect scorecard on Saturday.
Clarke, 34, mistakenly recorded a four instead of a five on the par-four 12th hole during the tournament's third round.
Meanwhile, Tiger Woods grabbed a one-stroke lead having chipped in for bogey, saved his share of pars and birdied the 18th hole after hitting into the grandstand to finish the second round at 12 under par.
Playing in his first event since undergoing knee surgery in December, Woods made five birdies, a bogey and three par saves of at least five feet on the back nine.
"It's great to be back," said Woods, who won this event in 1999. "It's great to get out there and compete again."
The top-ranked player in the world, Woods hit his second shot at the par-five 18th into the crowd to the right of the green.
But he took a drop, nearly holed his flop shot over a bunker and made a seven-foot birdie putt.
The birdie gave Woods a one-stroke lead over Brad Faxon, the second-round co-leader who played the last eight holes in two over en route to a 71.
Phil Mickelson set up an intriguing final threesome, shooting a 69 that put him in a tie for third with Steven Alker at 10 under.
Alker finished his round with an eagle.
Mickelson, a San Diego native who won this tournament in 2000 and 2002, began the week apologising for criticising Woods' equipment manufacturer Nike.
"It is going to be exciting to be in that final group again," said Woods.
204Tiger Woods 70 66 68
205Brad Faxon 70 64 71
206Steven Alker (Nzl) 69 67 70, Phil Mickelson 69 68 69
207Arron Oberholser 65 70 72, Briny Baird 70 65 72, Fred Couples 69 68 70, Jonathan Kaye 68 67 72, Carl Pettersson (Swe) 69 68 70
208Dennis Paulson 68 67 73
209Ben Crane 71 68 70, Mark Calcavecchia 71 67 71, Fred Funk 71 64 74, Len Mattiace 74 67 68
210Charles Howell III 74 68 68, Craig Perks 70 71 69, Luke Donald (Eng) 69 70 71, Rory Sabbatini (Rsa) 73 65 72, Bob Tway 68 68 74, Marco Dawson 68 66 76, Spike McRoy 67 71 72
211Joel Kribel 69 71 71, Chris Riley 72 67 72, Paul Stankowski 71 69 71, Dave Stockton Jr 72 69 70, Kirk Triplett 69 71 71, Skip Kendall 66 73 72, Neal Lancaster 71 65 75, Tom Lehman 71 71 69
212Dean Wilson 66 71 75, JJ Henry 75 67 70, Brian Watts 69 71 72, Bob Estes 74 69 69, Jay Haas 73 69 70
213Pat Perez 69 71 73, Tim Clark 70 70 73, Jose Coceres (Arg) 72 68 73, Jeff Brehaut 70 73 70, Alexander Cejka (Ger) 73 70 70, Brent Geiberger 72 69 72, Paul Goydos 74 67 72, Shigeki Maruyama (Aus) 73 70 70, Larry Mize 68 73 72, Corey Pavin 75 68 70, Brett Quigley 70 69 74, Kenichi Kuboya (Jpn) 72 67 74, John Morgan 67 72 74
214Mathew Goggin 69 72 73, Cameron Beckman 68 74 72, Joey Sindelar 70 71 73, Ken Green 74 67 73
215John Senden (Aus) 72 68 75, Todd Fischer 72 70 73, Thomas Levet (Fra) 69 72 74, Cliff Kresge 69 72 74, Steve Flesch 71 69 75, Doug Barron 69 72 74, Per Ulrik Johansson (Swe) 72 68 75, Steve Jones (Aus) 71 69 75, Scott Laycock (Aus) 77 66 72
216Heath Slocum 71 72 73, Jonathan Byrd 72 71 73, Notah Begay III 75 67 74, David Berganio Jr 73 70 73, Donnie Hammond 70 70 76
217Geoff Ogilvy 75 68 74, Tom Gillis 71 71 75, Kevin Sutherland 74 69 74, Woody Austin 73 69 75, Anthony Painter (Aus) 73 69 75
218Brenden Pappas (Rsa) 73 70 75
219Greg Chalmers (Aus) 71 71 77
220Gene Sauers 74 68 78
221Aaron Baddeley (Aus) 73 70 78
Disq Darren Clarke