A career-best round of 62 propelled England’s Harry Hall to the top of the leaderboard after the opening day of the Charles Schwab Challenge at Colonial Country Club.
He picked up eight birdies without dropping a shot and managed to save par from 15 and 30 feet.
Tom Hoge, Adam Schenk, Robby Shelton and Andrew Putnam are all tied for third on four under par.
Elsewhere, it was a mixed day for Scotland’s Russel Knox and English duo Callum Tarren and Justin Rose, who all head into Friday’s second round on one under.
Club professional Michael Block, who dazzled the golfing world with his heroics at the US PGA Championship heroics, had a rough outing as he finished his opening round 11 over par.