ACAPULCO (REUTERS/AFP) - Dustin Johnson surrendered a big lead before cementing his world No. 1 ranking with a one-stroke victory at the WGC-Mexico Championship in Mexico City on Sunday.
The American built a four-stroke advantage on the back nine before giving it all up to young Spaniard Jon Rahm at Club de Golf Chapultepec.
But Johnson, after back-to-back bogeys, avoided any further dropped shots in a three-under 68, tapping in at the last from a few inches.
He finished at 14-under 270 for his second consecutive victory, after winning at Riviera in California two weeks ago.
Englishman Tommy Fleetwood (66) birdied the last to claim second place on 13-under, while Rahm faded late to tie for third with Englishman Ross Fisher on 12-under.
Overnight leader Justin Thomas faltered with a 72 to finish three strokes behind, equal fifth.
Four-time Major champion Rory McIlroy, who could have overtaken Johnson atop the rankings with a victory, fired a 71 to share seventh with Americans Phil Mickelson and Brandt Snedeker on 274.
Johnson has now won 14 times on the PGA Tour, including four victories in World Golf Championships events.