MEXICO CITY (AP) The Mexico Championship put on quite a show in its debut as a World Golf Championships event.
So did Dustin Johnson.
In his first tournament as No. 1 in the world, Johnson gave every indication that he planned on staying at the top for a while.
Even during a week when everything seemed to go wrong - from a tee shot into the hedges and out-of-bounds to a shot that got stuck in a tree to the eight putts he missed from inside 5 feet - Johnson had enough resolve to hold off one last challenge and win the Mexico Championship.
It was his fourth World Golf Championships title.
He became the fifth player to win in his debut atop the world ranking.
The number that mattered was No. 1.
''My first week playing as No. 1, there's obviously a little bit extra pressure, a lot of limelight on me,'' Johnson said after closing with a 3-under 68 for a one-shot victory over Tommy Fleetwood of England. ''So to come out and win, it means a lot.''
It took more work at the end than he would have imagined.
What was supposed to be a riveting battle among some of the biggest names in golf turned into a one-man show. Johnson needed only a 31 on the front nine to dispatch of Justin Thomas, Rory McIlroy and Phil Mickelson.
He started the final round one shot out of the lead. He made the turn with a four-shot lead.
And then it was gone.
''Around here, anything can happen,'' Johnson said.
Jon Rahm, the 22-year-old rookie from Spain, rolled in an eagle and two birdies during a five-hole stretch on the back nine and took the lead when Johnson three-putted from 25 feet for bogey and then took another bogey from the bunker.
Johnson, however, is beyond the point where he expects something to go wrong. He kept his poise and regained a share of the lead with a tough bunker shot to make birdie on the par-5 15th, and then he allowed Rahm to make the mistakes.
The Spaniard had gone 59 holes without a three-putt, and then made two in a row to fall out of the mix. Johnson still wasn't in the clear. Leading by one shot over Fleetwood, who capped off his 66 with a 40-foot birdie putt on the last hole, Johnson hit a three-quarter shot out of the bunker from 127 yards away to the middle of the green for a two-putt par and a one-shot victory.
And yes, he's still No. 1.
''He has the potential to crack on for the next few years or a decade and be the dominant player, if he plays the golf we've seen him play,'' Paul Casey said.
Johnson sure felt like a star.
Walking through a roped-off corridor of fans between green-to-tee, Johnson stretched out his arms to slap hands or bump fists to everyone who wanted a piece of him. Children went from calling him ''Dus-TEEN'' to simply ''Dee-Jay.''
Life is good at the top right now.
''I try to put myself in a position to win every golf tournament,'' he said. ''Each week I go out, I'm prepared to win and I want to just give myself a chance to win when I turn to the back nine on Sunday.''
He won for the fifth time on the PGA Tour over his last 15 events dating to his U.S. Open victory last summer at Oakmont. He has won two WGC titles during that stretch, along with the FedEx Cup playoff event and the Genesis Open at Riviera, the strongest field of the year for a regular PGA Tour event.
Johnson stretched his lead in the world ranking over Jason Day, who chose not to play in Mexico because of an ear infection. He now gets two weeks off before he starts his run to the Masters at the Dell Match Play, the Shell Houston Open and then Augusta National. The Westgate Las Vegas Superbook listed him as the 6-to-1 favorite to win the Masters.
''Right now, the game is in good shape,'' Johnson said.
It was quite the consolation prize for the 26-year-old Fleetwood.
His 40-foot birdie putt on the final hole put him alone in second and secured a spot in the Masters for the first time. He moves to No. 35 in the world and is certain to stay in the top 50 over the next three weeks before the cutoff to get an invitation to Augusta National.
The other winner was Ross Fisher, who closed with three straight birdies for a 65 to assure a spot in the next WGC event in three week at the Dell Match Play.
Johnson now has won four World Golf Championships in the last four years. That's more than anyone except Tiger Woods, who won 18 of them from their inception in 1999. Asked if he could catch Woods, Johnson smiled.
''He's got a lot,'' Johnson said. ''But yeah, I'm going to try.''