Chris Kirk and Luke List each shot 7-under 65 on Saturday to share the third-round lead in the Sanderson Farms Championship.
Kirk and List were at 14-under at the Country Club of Jackson.
Cody Gribble (67), Canada's Graham DeLaet (68), and 2009 U.S. Open champion Lucas Glover (68) were a stroke back.
Second-round leader Grayson Murray had a 72 to drop two shots behind. He missed several short putts and had a double bogey on the shortest par-4 on the course.
Kirk, the highest-ranked player in the field at 76th, had eight birdies and a bogey.
Kirk's first PGA Tour title came in the event in 2011, when it was known as the Viking Classic and was played at Annandale Golf Club in nearby Madison. He has won three times since, including twice in 2014, when he finished second in the FedEx Cup standings.
List, chasing his first PGA Tour victory, had seven birdies in a bogey-free round.