Dustin Johnson extended his lead over Rory McIlroy to four shots on the third day of the WGC-Mexico Championship as the Northern Irishman had to rally from a scrappy start.

McIlroy bogeyed three of the first eight holes but made the turn at level par after a 34-foot birdie putt on the ninth.

The 29-year-old then closed strongly to salvage a round of 68 with four birdies and one bogey on the back nine.

That was not enough to keep pace with Johnson though, despite the American making a double bogey on the par-four 10th.

Johnson eagled the second hole after a superb tee shot and made the turn in 32. He then bounced back from his setback on the 10th with four birdies in the last eight holes. Johnson is on -16, McIlroy on -12.

Patrick Reed had two eagles in a round of 64 that lifted him up 17 places and into a four-way share of third, seven shots back, alongside Patrick Cantlay, Sergio Garcia and Cameron Smith.

Tiger Woods' round fell apart late on as he could only manage a 70, dropping down into a share of ninth place.

Woods was on course for much better until he four-putted the par-five 15th for a double-bogey and dropped another shot on the 16th, though he birdied the 18th to limit the damage.

He declined to speak to the media afterwards, something he has done only a handful of times over his career.