Sebastian Munoz shot 63 for a 16-under-par total of 200 to grab the lead after three rounds of the Sanderson Farms PGA Golf Championship in Jackson, Mississippi.
The Colombian's bogey-free round, which included back-to-back birdies on the 11th and 12th, left him a stroke clear of Mexico's Carlos Ortiz.
An eagle on the 11th was the highlight of Ortiz's round of 65 which nudged him above the overnight leader, Byeong Hun An of South Korea.
An, who had been forced to play 25 holes on Friday due to bad weather, looked set to extend his lead after three straight birdies put him at four-under-par for his round after 15 holes.
But a late lapse in which he posted consecutive bogeys on the 16th and 17th holes saw An drop back to 70, and a 14-under-par total of 202.
Cameron Percy shot a round of 68 to finish the day in fourth place on 13-under for the tournament, with five players, including another Korean, Sungjae Im, a further shot behind.
