Dustin Johnson wins the WGC-Mexico Championship

The US Open champion maintains his spot at the World number one

Dustin Johnson wins the WGC-Mexico Championship

Picture by: Christian Palma/AP/Press Association Images

Dustin Johnson's first tournament as World number one, end with him winning the WGC-Mexico Championship, on Sunday night in Mexico City.

The US Open champion finished on -14 at Chapultepec Golf Club, one shot clear of England's Tommy Fleetwood. Former Irish Open winner Ross Fisher and Spanish prospect Jon Rahm finished in a tie for third on -12.

Rory McIlroy had a disappointing final round. On his comeback from a rib injury, the Hollywood golfer shot a level-par 71 to finish in a tie for seventh place, on -10.

Speaking after the win Johnson said to win on his first start at the top of the World rankings was extremely satisfying.

"Well, it means a lot. Obviously getting to number one, it's the first time I've been there, so my first week playing as number one, there's obviously a little bit extra pressure, a lot of limelight on me. So to come out and win, it means a lot. I'm very proud of the way I played this week and obviously getting this victory, it means a ton".

The 32-year-old started the final round in Mexico City on -11, one shot behind Justin Thomas. Johnson overtook Thomas after the sixth hole, going out in an impressive 31 on the front nine. Consecutive bogeys on the 12th and 13th gave Johnson a wobble, but a birdie on 15 steadied the ship.

Jon Rahm was Johnson's major rival on the back nine, despite eventually slipping back to third place. A bogey-bogey finish ruined the Spaniard's chances of a first WGC win despite being tied for the lead on the 17th tee.

Rory McIlroy was one of only three players in the top-ten, not to shoot a sub-par final round. The World number three was leading by two shots at the midway stage, but fell back over the weekend.