Thomas made nine birdies in his first 12 holes en route to a closing 62.
Justin Thomas started the final round of the WGC-Mexico Championship at even par, well out of contention. Perhaps playing with an added sense of freedom, he came out firing and tied his own Club de Golf Chapultepec record with a nine-under 62.
Thomas, who lost in a playoff to Phil Mickelson at this event last year, got off to an absolutely torrid start after starting on the back nine. He birdie each of the first four holes and turned in five-undr 31, then started his back side with three more birdies, bringing his total to nine over 12 holes.
Thomas was dialed in with his irons; multiple landed within a couple feet of the hole, including his tee shot at the par-3 3rd that then spun back and rolled down a ridge to some 40 feet.
He would add his 10th and final birdie at the par-5 6th and finished with three straight pars.
His birdie effort on 9, which would have been for 61, slid by just on the right side. The 62 matched his own record from the third round last year, when he shot 62-64 on the weekend to get into the playoff.
The damage was done mostly with the putter—he picked up 3.34 shots on the field putting for the round and holed three putts of at least 25 feet.
It will likely be another top-10 finish for the world No. 4, who blew a four-shot lead and finished second at last week's Genesis Open.