Retief Goosen shot a superb eight-under-par 64 to surge to the top of the leaderboard after two rounds of the Pebble Beach National Pro-Am, seizing a two-shot advantage over Dustin Johnson.
An eagle on the first hole provided the perfect start to the round by the South African, who moved to 12-under 132 for the tournament.
First-round co-leader Johnson is alone in second place following a three-under 69.
Starting on the back nine, Johnson also got going quickly with four birdies in his first six holes before a double-bogey at the 17th hole slowed him down.
Robert Garrigus, who shared the first-round lead with Johnson after an opening 66, carded a 71 and is tied with Charley Hoffman, Mike Weir and Mark Calcavecchia in third place on eight-under 136.
Seeking his first career win, Garrigus got off to a bumpy start with back-to-back bogeys on holes five and six but managed to battle back and get under par for his round.
Hoffman had a roller-coaster round that featured an eagle, a double-bogey, two bogeys and four birdies en route to a two-under 70.
Weir shot level par 36 on the front nine before picking up three birdies after the turn to sign for a round of 69.
Defending champion Steve Lowery started his round on the back nine and birdied four of his first five holes to climb to five-under for the tournament.
Last year, Lowery broke an eight-year victory drought and picked up his third PGA Tour title with a birdie on the first play-off hole to outlast Vijay Singh.
2002 US PGA champion Rich Beem birdied the first two holes to climb to eight under before bogeying five of his final 12 holes to finish at three-under through two rounds.
Singh is also in the field this week, making his second start of the season. He struggled Friday with four bogeys and a birdie to fall to three over par.
The winner of this event in 2004, Singh is making his return to the Tour after undergoing arthroscopic surgery on his right knee in mid-January.
Jim Furyk and Phil Mickelson are at three-under at one-under respectively.
Furyk is coming off a 2008 season in which he led the tour in top-10 finishes with nine. However, he failed to record a victory for the first time since the 2004 season.
Mickelson has had success here, as the Pebble Beach Pro-Am is one of four events he has won three or more times. Mickelson, who won here by five strokes in 2007, has five top-three finishes in 13 appearances.
Three-time major champion and reigning PGA Player of the Year Padraig Harrington sits at three-over after the second round.
Collated second-round scores (USA unless stated, par 72):
Pebble Beach GC
132 Retief Goosen (Rsa) 68 64
136 Mark Calcavecchia 67 69, Mike Weir (Can) 67 69
137 Aron Price (Aus) 68 69
138 Chris Stroud 69 69
139 Sean O'Hair 71 68, Dean Wilson 68 71
140 Bob Estes 68 72
141 Peter Tomasulo 71 70, Kenny Perry 71 70, Richard S Johnson (Swe) 71 70, Todd Fischer 72 69, Matt Bettencourt 68 73
142 Brian Vranesh 68 74, Derek Fathauer 71 71, Kevin Stadler 71 71, J.B. Holmes 74 68, Todd Hamilton 71 71, Rick Price 70 72, Matthew Jones (Aus) 71 71, Alex Cejka (Ger) 73 69
143 Dudley Hart 71 72, J J Henry 71 72, Omar Uresti 71 72, John Ellis 69 74, Greg Chalmers (Aus) 71 72, James Driscoll 73 70, Frank Lickliter II 72 71, Mark Wilson 70 73
144 Nick Watney 75 69, Jimmy Walker 71 73, Rob Grube 72 72, Andrew Magee 74 70
145 Colt Knost 72 73, Tag Ridings 72 73, Darron Stiles 73 72, Tom Lehman 71 74, Jeff Klauk 73 72, Marc Leishman (Aus) 72 73, Jay Williamson 70 75, Jonathan Byrd 71 74, James Oh (Kor) 73 72
146 Billy Andrade 74 72, Joel Sjoholm (Swe) 70 76, Daniel Chopra (Swe) 75 71, Robert Damron 77 69, Tom Pernice Jnr. 72 74
147 Vijay Singh (Fij) 72 75, Brendon Todd 74 73, Olin Browne 72 75, Padraig Harrington (Irl) 74 73
148 Kevin Na 71 77, Brent Geiberger 73 75, Jason Bohn 75 73
149 Paul McGinley (Irl) 72 77
150 Robert Gamez 76 74
152 Marc Turnesa 77 75
154 Troy Kelly 75 79, Carlos Franco (Par) 75 79
156 Jason Schmuhl 76 80
Poppy Hills GC
136 Charley Hoffman 66 70, Robert Garrigus 65 71
139 Will MacKenzie 70 69, Ryan Moore 72 67
140 Tim Herron 72 68, Kevin Chappell 68 72, Matt Weibring 70 70
141 Jeff Maggert 69 72, Jim Furyk 71 70, Fredrik Jacobson (Swe) 68 73
142 Michael Letzig 69 73, Tom Scherrer 68 74, Brandt Snedeker 71 71, Tim Clark (Rsa) 71 71, Charles Howell III 72 70, Steve Elkington (Aus) 67 75
143 Brian Davis (Eng) 72 71, Gary Woodland 71 72, Steve Allan (Aus) 73 70, Fred Couples 73 70, Phil Mickelson 72 71, Mathew Goggin (Aus) 70 73, Bo Van Pelt 70 73, Ken Duke 71 72, Glen Day 73 70
144 Pat Perez 73 71, Chris DiMarco 70 74, Brett Quigley 72 72, Tim Petrovic 72 72, Bryce Molder 76 68, Corey Pavin 74 70, Jesper Parnevik (Swe) 73 71, Jason Gore 75 69
145 Brad Faxon 72 73, Chris Riley 75 70, Paul Stankowski 74 71, Clint Jensen 76 69, Kevin Streelman 70 75, Webb Simpson 71 74, Tommy Gainey 71 74
146 Kent Jones 72 74, Joe Durant 73 73, Marco Dawson 76 70, Notah Begay III 76 70, Greg Kraft 74 72, Kevin Sutherland 74 72
147 Ryan Palmer 74 73
148 Skip Kendall 75 73, Nicholas Thompson 73 75
149 Kirk Triplett 71 78, Kyle Thompson 78 71, Scott Sterling 77 72, Parker McLachlin 76 73
151 Patrick Sheehan 77 74, Scott McCarron 74 77, Garrett Willis 75 76
152 D.A. Points 73 79
154 Jay Delsing 79 75, Dicky Pride 77 77, Tommy Armour III 76 78
Spyglass Hill GC
134 Dustin Johnson 65 69
137 Charlie Wi (Kor) 68 69, Bill Lunde 67 70, Mark Brooks 68 69
138 Michael Allen 67 71
139 Y. E Yang (Kor) 69 70, Jeff Overton 69 70, Steve Lowery 70 69
140 Ted Purdy 68 72, Bob Heintz 71 69, D.J. Trahan 67 73
141 Spencer Levin 71 70, Vaughn Taylor 66 75, Davis Love III 69 72, Jeff Quinney 68 73, Greg Owen (Eng) 68 73, Arjun Atwal (Ind) 68 73, Len Mattiace 69 72, Rich Beem 66 75
142 Jonathan Kaye 69 73, Matt Kuchar 71 71, Shigeki Maruyama (Jpn) 69 73, Jason Day (Aus) 67 75
143 Brad Adamonis 71 72, Brendon De Jonge 69 74, Charles Warren 74 69, Jason Dufner 75 68, John Mallinger 72 71, Hunter Mahan 72 71, Craig Barlow 73 70, Scott Gutschewski 71 72
144 Ricky Barnes 69 75, KJ Choi (Kor) 69 75, Casey Wittenberg 72 72, Steve Flesch 72 72, Eric Axley 72 72, Lee Janzen 71 73, Troy Matteson 73 71
145 Jarrod Lyle (Aus) 72 73, Paul Goydos 68 77, Joe Ogilvie 71 74, Chris Smith 70 75, David Duval 73 72, Brian Bateman 71 74
146 Chris Kirk 73 73, John Huston 70 76, David Mathis 71 75, Matthew Borchert 72 74, Tyler Aldridge 70 76
147 Michael Thompson 72 75
148 Aaron Watkins 73 75, Kris Blanks 76 72, Zack Miller 69 79, J.P. Hayes 72 76, Wil Collins 74 74
149 Leif Olson 75 74, David Toms 74 75, Johnson Wagner 73 76
151 Bobby Clampett 75 76
160 Robert Floyd 80 80
