Chris Kirk shot an 8-under 63 on Thursday to take a one-stroke lead in the OHL Classic at Mayakoba.
Kirk had four birdies on each nine in his bogey-free round on Mayakoba's Greg Norman-designed El Camaleon course. He won the last of his four PGA Tour titles in 2015.
The former University of Georgia player has two top-10 finishes in three starts in the new PGA Tour season, opening with a tie for eighth at Silverado and tying for second in Mississippi.
Camilo Villegas, Gary Woodland and Ben Crane were tied for second.
Mexico's Abraham Ancer bogeyed the final hole for a 65. NCAA champion Aaron Wise also was 65 along with Webb Simpson, Scott Piercy, Kevin Streelman and Nicholas Lindheim.
Jim Furyk had a double bogey in a 74 in his first round of the season.
Defending champion Graeme McDowell opened with a 75.