Viktor Hovland is on track to retain his World Wide Technology Championship at Mayakoba title after a birdie spree sent him to the top of the leaderboard following the third round.
Defending champion Hovland carded a career-low nine-under-par 62 on Saturday to soar to the Mayakoba summit at El Camaleon Golf Club, where he leads by two strokes.
The Norwegian star was flawless, holing nine birdies without a bogey, as he overturned a three-shot deficit on the penultimate day, with overnight leader Matthew Wolff crumbling (74).
"I got the max out of my game, essentially," said Hovland, who is bidding to become the first player to go back-to-back at the PGA Tour tournament.
"I did hit some approaches that were 40 feet, 30 feet and even 50 feet and when that kind of happens, you're just expecting to two-putt and move on. Then when I did hit a nice approach shot, I took advantage of it.
"So I felt like I got max out of my game, but obviously to shoot 59 you've got to chip in and you've got to hole a 50-footer or some longer putts and I didn't quite do that today, but I'm not too disappointed.
"That was fun today. Obviously I got off to a nice start and it was nice to have one of those rounds where you can kind of keep it going throughout the day instead of maybe slowing down towards the end there where, frankly, there are some tough holes."
Hovland is 19 under overall through 54 holes, two shots clear of Talor Gooch (63) and three ahead of former world number one Justin Thomas (64).
Wolff – who led entering the weekend – had a nightmare round, having bogeyed four holes to be tied for 17th, nine shots adrift of Hovland heading into Sunday's decider.
American pair Rickie Fowler (69) and Patrick Reed (70) are tied for 54th and 60th respectively.