Dustin Johnson survived a few anxious moments on the back nine by playing mistake-free when it mattered to win the Mexico Championship in his debut as the No. 1 player in the world.
Johnson blasted out of a fairway bunker to the middle of the 18th green to secure a two-putt par for a 3-under 68 and a one-shot victory over Tommy Fleetwood of England.
Johnson became the fifth player to win in his debut at No. 1, and his fourth World Golf Championship title is second on the career list behind Tiger Woods, who won 18 since the series began in 1999.
Fleetwood made a 40-foot birdie putt on the 18th for a 66, which locks up a spot in the Masters.