Justin Thomas made bookend bogeys but piled up eight birdies in between en route to a one-shot lead over Patrick Reed and Erik van Rooyen at the WGC-Mexico Championship on Saturday.
On a day when overnight leader Bryson DeChambeau self-destructed, Thomas carded six-under-par 65 at Club de Golf Chapultepec in Mexico City.
Two years after losing a playoff to Phil Mickelson, Thomas has a chance to avenge that near-miss, going into Sunday's final round at 15-under 198.
Fellow American Reed (67) hit an unusually poor bunker shot to bogey the final hole and slip back into a tie for second with South African van Rooyen (67).
American DeChambeau struggled to a 71 and fell back into a tie for fourth with Spaniard Jon Rahm (61) and Northern Irishman Rory McIlroy (68), four strokes from the lead.
Rahm's course record include a hole-in-one at the 17th.
(Reporting by Andrew Both in Cary, North Carolina; Editing by Christian Radnedge)
