Robby Shelton carded an eight-under-par 62 to lead the Greenbrier Classic after the opening round.
At the 2019-20 PGA Tour season-opening event, Shelton was almost flawless as he earned a two-stroke lead on Thursday.
Shelton – who turned professional in 2016 – had nine birdies and a bogey to finish day one ahead of fellow Americans Scott Harrington, Mark Hubbard, Kevin Na, Lanto Griffin and Zack Sucher.
The 24-year-old Shelton has spent time on multiple golf circuits, including the Mackenzie Tour in Canada and the Korn Ferry Tour.
Defending champion Na was in peak form to start the week but a bogey on his front nine kept him in a five-way tie for second place on The Old White TPC at The Greenbrier.
There is a sizable tie for seventh place at five under, with 10 golfers looking to play into the weekend, and even more just one stroke behind in 17th place.
Im Sung-jae is included in the 15-way tie at four under following his first-round 66.
Named Rookie of the Year last season, South Korean Im reached an impressive milestone after recording a hole-in-one on the par-three 15th hole.
Im became the first player on Tour to have two or more aces before the age of 22 since superstar Tiger Woods.
Bubba Watson (69), Branden Grace (70) and J.B. Holmes (71) are also playing this weekend but well behind the leaders.