Patrick Reed carded a four-under 67 to win the WGC-Mexico Championship. Joint second overnight the 29-year-old world number 14 could afford to bogey the last as he finished 18 under, one ahead of compatriot Bryson DeChambeau who had serious putting woes.
World number four Justin Thomas, one ahead at the beginning of the final day, fell to a 73 on a sixth share.
Jon Rahm’s 67 left him with three third-place adrift, with Rory McIlroy’s world number one shot back after a 68.
Following nine birdies and a hole in one in a course record 61 on Saturday, Rahm birded four of the first five holes to take a share of the lead and then managed to rescue par when his second shot found the water in the sixth.
In comparison Thomas, looking for his 13th PGA win, saw his tee shot flip off a tree into the water at the par-three seventh and fell out of the lead when another shot went to the next after his drive was 80 yards off target.
His ball then ended behind the base of a tree causing him to play left-handed, and while finding a way back to the fairway through the trees, a double bogey resulted.
With other leading players struggling to catch the momentum, DeChambeau, playing with Rahm and McIlroy in the penultimate group made seven birdies from sixth in nine holes to pull two clear.
The illustrious Rahm and McIlroy were only able to play back nine in level par, but the ever-tenacious Reed made two birdies to reduce the gap to one and was tied for the lead when DeChambeau left himself at 17th 63 feet away, which resulted in a 3-putt.
With a low sun creating visibility issues at the Chapultepec Golf Club, Reed produced a birdie on 16 and took the lead.
DeChambeau, who led after two rounds, missed a 19-foot birdie chance at the last to finish with a 65 for 17 under, with Reed rattling in a long putt at the 17th in a third successive birdie.
There was still time for suspense when Reed shot it back into the woods, taking an iron off the tee at the final hole, but reached the green in three and comfortably two putted for a five to add a second WGC title to his 2018 Masters win.
Patrick Reed WITB 2020
Driver: Ping G400 LST, (9° Fujikura Ventus Black 70X shaft)
3-wood: TaylorMade M6, (15° Aldila Rogue Silver 125 80 TX shaft)
Hybrid: Callaway Apex, (18° Aldila RIP Phenom 100X shaft)
Driving iron: Titleist T100, (3-iron, True Temper Dynamic Gold Tour Issue AMT X100 shaft)
Irons: Grindworks Reed Prototype blades (4-PW, True Temper Dynamic Gold Tour Issue X100 shafts)
Wedges: Artisan Prototype, (51°), Titleist Vokey SM7 (56° & 60° True Temper Dynamic Gold Tour Issue S400 shafts)
Putter: Scotty Cameron Prototype
Ball: Titleist Pro V1