Tyler Duncan opened up a two-stroke lead at the halfway mark of the RSM Classic on Friday.
The American carded a nine-under 61 on the Seaside course at Sea Island Golf Club in Georgia to climb to the top of the leaderboard at 14 under.
Duncan holed an eagle – from 106 yards at the par-four eighth – and seven birdies during a fine second round.
He sits clear of Colombian Sebastian Munoz (63), Australian Rhein Gibson (64) and American D.J. Trahan (63).
Of that trio, only Trahan played the Plantation course on Friday, shooting an impressive nine-under round to get to 12 under.
Ricky Barnes (63 on Plantation) and Fabian Gomez (63 on Seaside) are tied for fifth at 11 under.
Webb Simpson, the overnight leader, could only manage a two-under 68 on the Seaside course to fall to a tie for 11th at nine under.
Defending champion Charles Howell III missed the cut after backing up his opening-round 68 with a 72.