Justin Leonard shares the lead with three other players as round one of the OHL Classic at Mayakoba was suspended due to darkness.
Americans Leonard, Shawn Stefani, Derek Fathauer and Australian Aaron Baddeley carded six-under-par 65s in Playa del Carmen, Mexico on Thursday.
The quartet are a shot clear as fading light forced an early finish at El Camaleon Golf Club, with 21 players yet to finish their opening rounds.
But Leonard, Stefani, Fathauer and Baddeley managed to complete 18 holes at the picturesque Mexican course.
Leonard - the 1997 Open champion and 12-time PGA Tour winner but without a win since 2008 - posted six birdies in his flawless first round.
Fathauer was also bogey-free, while Stefani and Baddeley both dropped shots.
Michael Thompson, D.J. Trahan, Charles Howell III and Patton Kizzire are tied at five under.
A total of 15 players are a shot further back, including 2010 U.S. Open champion Graeme McDowell, 2011 OHL Classic at Mayakoba winner Johnson Wagner and Keegan Bradley.
Hunter Stewart is among that group, with the American through 15 holes at the close of play.
Peter Malnati, winner of the Sanderson Farms Championship on Monday, is three strokes behind the leaders.
Defending champion Charley Hoffman holed a first-round 71 to be even par heading into the second day.
Meanwhile, South African Thomas Aiken made a dream start but faded dramatically.
Aiken eagled his opening hole at the 10th and followed that up with back-to-back birdies.
But he struggled on the front nine, registering two bogeys and a double-bogey from his final four holes.