America's Jimmy Walker shot a second-round 62 to surge into the lead of the Wyndham Championship in Greensboro, North Carolina.
Walker, who opened with a 66 yesterday, enjoyed a bogey-free eight-under-par round as he moved to 12 under and into the clubhouse lead, two shots clear of the chasing pack.
The 33-year-old leads from fellow American Harris English, who followed up yesterday's 66 with a 64, while South Africa's Tim Clark (67) and Spain's Sergio Garcia (63) were also at 10 under.
First-round leader Carl Pettersson hit two bogeys and one birdie over his front nine today to drop to seven under par and a tie for seventh place as he reached the turn.
Elsewhere, Tim Herron recovered from a dismal opening 76 by setting a new course record with a stunning nine-under-par 61.
The American began the second day lying 155th in the 156-man field, but surged up the leaderboard and into a tie for 41st place on three under.
Herron turned in 32 after four birdies and a bogey, before a birdie at 10 was followed by five in a row from the 13th as he posted 29 on the back nine.
