Charles Howell fired six birdies in a six-under par 64 to stretch his lead to three strokes in the PGA Tour RSM Classic in Sea Island, Georgia.
Howell, a two-time US PGA Tour winner but chasing his first title in more than a decade, kept the accelerator down on the par-70 Seaside course, a day after nabbing eight birdies on the par-72 Plantation course.
He goes into the weekend 14-under on 128, three shots ahead of rising star Cameron Champ, 23, who won his first title at the Sanderson Farms Championship last month, and Jason Gore.
Both signed for 63s on the Seaside course to share second on 131. Howell said another wind-whipped day felt "a little bit like survival" but that he benefitted from the focus the conditions required.
"It sort of forces you to play so much in the present," he said. "It's kind of hard to get too far ahead of yourself because you know there's plenty of hard ones coming up."