Patrick Reed outlasted fellow American Bryson DeChambeau for a one-stroke victory at the WGC-Mexico Championship on Sunday, with Rory McIlroy having to be satisfied with a fifth-place finish. 

Reed took the lead with a tap-in birdie at the 16th hole and went further ahead with another birdie at the 17th at Club de Golf Chapultepec in Mexico City.

Though he bogeyed the last after a wild drive, his cushion proved enough, with a four-under-par 67 sealing the deal.

Reed finished at 18-under 266 for his eighth PGA Tour victory, and his second at the World Golf Championships event, his previous one coming at Doral in Florida in 2014.

Six players were bunched within one stroke of the lead halfway through the final round, before DeChambeau seemingly seized control with five birdies in six holes.

But DeChambeau's charge petered out, and a three-putt bogey at the 17th pretty much ended his chances.

He shot 65 for 17-under 267, with Spaniard Jon Rahm and South African Erik van Rooyen two shots further back in a tie for third.

McIlroy finished four shots behind after carding a 68. A bogey on the 12th stalled his momentum after three earlier birdies. He did recover to find another birdie on 16.   

American overnight leader Justin Thomas hit several wayward drives, shooting 73 and plunging five shots back.