REUTERS: Dustin Johnson drove the green at the par-four second hole for an eagle en route to a four-stroke lead over Rory McIlroy after the third round of the WGC-Mexico Championship on Saturday.
The hot start afforded the world number three the luxury of maintaining a healthy buffer despite a double-bogey at the 10th hole at Club de Golf Chapultepec in Mexico City.
The American shot five birdies as well as the eagle for five-under-par 66 to move to 16-under 197 for the tournament and remain on course for a second win in three years at the World Golf Championships event.
Northern Irishman McIlroy, who led after the opening round, mixed seven birdies with four bogeys for a 68 to stand alone in second place on 12-under.
Spaniard Sergio Garcia, Americans Patrick Reed and Patrick Cantlay and Australian Cameron Smith were a distant seven strokes back in a share of third.
Tiger Woods had problems on the greens, four-putting at the 15th and three-putting the next, to slip 10 strokes off the lead with a 70.
(Reporting by Andrew Both in Cary, North Carolina, editing by Nick Mulvenney)