Kim Si-woo took the solo lead at the Texas Open after shooting a six-under 66 in the opening round on Thursday.
The South Korean got off to a good start, but truly closed it out well as he birdied five of his last eight holes.
The finish gave him a one-shot lead over several players at five under and put him two clear of Jordan Spieth and Rickie Fowler, who finished their days at four under.
Fowler was one shot back until his second-last hole at the eighth, where he tallied a bogey at the par five.
A good start though put him in position to climb towards the top of the leaderboard.
"It's always nice to get out and make some birdies early, shake off some rust," Fowler told reporters, via Golf Week.
"Happy with where we're at going into tomorrow, but also looking forward to the weekend with some work to do tomorrow as well as how I feel about the game going into next week. So really only one blemish, the tee shot on our 17th hole, number eight, but other than that, solid day of golf and some good work."
Spieth, the 2015 runner-up, had some trouble closing out his round as well, but a birdie at the par-four 17th got him back to within two shots of Kim.
J.T. Poston, Abraham Ancer, Brian Stuard and Jhonattan Vegas are the group at five under.
Matt Kuchar is one shot back of Spieth and Fowler at three under while Jim Furyk is at two under.
Defending champion Andrew Landry opened with a one-under 71 to be tied for 52nd.