John Rollins shot a third-round 68 on Saturday to take a two-shot lead into the final day of the Sanderson Farms Championship in Mississippi.
The American finished two strokes worse off than his 66 on Friday by sinking five birdies and a bogey at the sixth to move into the fourth round on 14-under-par.
Rollins, who won the last of his three PGA Tour titles back in 2009, is being pursued by William McGirt, who shot 66 to move two shots adrift of his compatriot.
Jason Bohn and Lucas Glover sit three shots off the pace on 11-under, while overnight co-leader David Toms - who led with Rollins - endured a disastrous front-nine to jeopardise his title bid.
Toms picked up three successive bogeys from the fourth hole onwards, but managed to sink two birdies at 10 and 18 to leave him in contention ahead of Sunday on 10-under, along with Canada's Nick Taylor.