Russell Knox's bogey-free 65 earned him top spot on the Valero Texas Open leaderboard after the first round of action at TPC San Antonio.
The Scotsman was excellent all day, highlighted by his four consecutive birdies starting on the 12th hole to finish seven under.
He is one stroke ahead of Denmark's Rasmus Hojgaard, who eagled the par-five 18th to finish at six under and make up for his double-bogey on nine.
Speaking to the media after his round, Knox spoke about getting control of his driver, and the potential to play in next week's US Masters.
"I would love to win and get to play next week," he said.
"I know my game is good, so I've got to keep playing well and see if I can have a great finish.
"I've been a little more consistent tee to green. I'm back to kind of feeling like the way I should be playing, which has been nice.
"Off the tee's been kind of important for me. Over the last couple years I just kind of got off track slightly, hitting a few wayward tee shots.
"I've worked hard with my coach, Mark McCann, and we've really gone back to fundamentals, got my set-up correct and it just gives me the freedom to kind of swing away.
"I know it's never going to be perfect, but the last couple months it's really been a strength of mine again."
Matt Kuchar and Englishman Aaron Rai are in a four-player tie for third at five under, with India's Anirban Lahiri and Australian Matthew Jones part of the large contingent at four under.
In-form Canadian Corey Conners finished tied with Richard Bland and Tony Finau with a big group at two under, with Ian Poulter and Keegan Bradley one shot further back.
It was an up-and-down round for Rickie Fowler, with his bogey on 18 forcing him to accept even-par for the day, which he shared with stars Rory McIlroy and Jordan Spieth.
Bryson DeChambeau and Lee Westwood highlighted the group at plus one, while Jason Day and Hideki Matsuyama will be fighting to make the cut after carding plus two.