Noh Seung-yul, Tom Hoge and Shawn Stefani are in a three-way tie for the lead after the opening round of the St. Jude Classic.
The trio carded five-under-par 65s to earn a one-stroke lead atop the leaderboard in Memphis, Tennessee on Thursday.
Noh earned a share of the lead after birdieing the 18th, while U.S. Open contender Dustin Johnson was on track to force a four-way tie but the American bogeyed his final hole at TPC Southwind.
The final tournament before next week's U.S. Open - the second major of the season - the St. Jude Classic provides players with an opportunity to build some form heading to Oakmont.
And Noh, Stefani and Hoge led the way, with the latter stealing the show.
Hoge was flawless, holing five birdies without dropping a shot, while Noh had six birdies and a bogey.
Stefani posted an eagle, six birdies and three bogeys in a mixed round.
Johnson, Jamie Donaldson, Brian Gay, Steve Stricker, Colt Knost and Miguel Angel Carballo are level at four under.
Stricker birdied his closing three holes to move within a shot of the lead, while Donaldson and Knost had two birdies from their final three holes.
Brian Stuard, Retief Goosen, Justin Leonard, Brett Stegmaier, Daniel Berger, Scott Stallings, Wes Roach and Henrik Norlander are all a shot further back.
Phil Mickelson carded an opening-round 70, a score matched by defending champion Fabian Gomez and South African Ernie Els.