United States pair Bubba Watson and Webb Simpson share the lead ahead going into the final round of the Zurich Classic in New Orleans.
Watson led by a shot at the start of Saturday's play in Louisiana but, after going one over through the first six holes, he found himself tied for fifth.
Watson recovered to card a 70 while Simpson (67) shot up the leaderboard.
John Rollins (69) is a shot off the lead on 11 under par, with England's Luke Donald back on seven under.
Watson, who is hoping to collect his second title in three months following victory at Torrey Pines earlier this year, admitted he did not have things all his own way on the greens.
"The greens are getting pretty quick," Watson said. "It was tough making putts. I was just trying to cozy the ball up there."
US players dominate the top of the leaderboard, with four Americans - George McNeill (65), Charles Howell III (66), Tommy Gainey (68) and Steve Stricker (68) - two shots off the lead on 10 under, along with Korea's KJ Choi (67) and Australia's Matt Jones (69).
Simpson was five under through the first eight holes of his round to finish on 12 under.
He landed five stunning birdies in a row to hijack the title fight, and was hotly followed by Rollins and Howell, who was six under for the day with five holes left to play.
Donald, who needs a top-two finish at the $6.4m (£3.83m) event to have a chance at overtaking Lee Westwood and become world number one, was six shots off the lead after 10 holes, shaving one shot off his overall total on the day.