Charley Hoffman carded an eight-under-par 64 to earn a share of the one-stroke lead after the opening round of the Sanderson Farms Championship.
Hoffman ended Thursday level atop the leaderboard alongside Jimmy Walker, Kevin Chappell and defending champion Sebastian Munoz in Jackson, Mississippi.
A four-time PGA Tour champion but without a title since 2016, Hoffman was almost flawless as he holed nine birdies and just one bogey at the Country Club of Jackson.
Hoffman reeled off four successive birdies, starting on the third, before going bogey-free on the back nine.
Walker and Chappell were both flawless throughout their first rounds, while Munoz opened his title defence by only dropping one shot.
Michael Gligic and MJ Daffue are a stroke off the pace heading into Friday's 18 holes, a shot better off than Anirban Lahiri, J.T. Poston, Keegan Bradley, Talor Gooch and Cameron Davis.
Former Masters champion Sergio Garcia posted a 68, while Hudson Swafford recorded a three-over-par 75 following his Corales Puntacana Resort and Club Championship triumph.