MEXICO CITY — The only elevation that mattered at the Mexico Championship is how much higher Dustin Johnson can go.

In his first start since a five-shot victory at Riviera that made him No. 1 in the world, Johnson captured his fourth World Golf Championships title Sunday by blowing past some of golf’s biggest names and then delivering his best shot at the end to secure a one-shot victory over Tommy Fleetwood of England.

He won for the fifth time in his last 15 starts on the PGA Tour, including a major and two World Golf Championships.

And at nearly 7,800 feet above sea level at Chapultepec Golf Club, Johnson kept soaring.

He closed with a 3-under 68, and finished this one off with one of the most difficult shots in golf. Clinging to a one-shot lead, his feet on the edge of the bunker and ball below his feet, Johnson hit a three-quarter shot from 127 yards with his 54-degree wedge to the middle of the 18th green for a two-putt par.

He called it a “dink.” He also could have called it clutch.

“Probably the best shot I hit all week, especially under the circumstances, was that second shot on 18,” he said. “A fantastic shot.”

It wrapped up a spectacular week in Mexico City, which hosted this World Golf Championship after it had been at Trump Doral the last seven years.

Johnson walked through the roped corridors with his arms extended to slap hands and bump fists with an energetic crowd, especially kids who called out, “Dee-Jay!”

Johnson finished at 14-under 270.

Justin Thomas had a one-shot lead over Johnson, with Rory McIlroy and Phil Mickelson another shot behind. It was an All-Star cast that Johnson turned into a one-man show with a 31 on the front nine to build a four-shot lead.

And just like that, it was gone.

“Around here, anything can happen,” Johnson said.

Thomas fell back with a double bogey in the water on the par-3 seventh. But neither McIlroy nor Mickelson got anything going.

The challenge came from Jon Rahm, the dynamic rookie from Spain, who made an eagle and two birdies in a five-hole stretch on the back nine. That’s right when Johnson had his only real struggles, three-putting from 25 feet for bogey on No. 12 and taking bogey from a bunker on No. 13.

LPGA: Inbee Park used self-described “amazing” putting to win the HSBC Women’s Champions by one stroke at Sentosa Golf Club in Singapore.

The South Korean closed with an 8-under 64, making a bogey on the final hole to finish at 19-under 269. Playing partner Ariya Jutanugarn was second after a 66.

Sung Hyun Park (68) was third at 16 under, and third-round leader Michelle Wie (72) was 14 under with 2016 winner Ha Na Jang (69) and Brooke Henderson (66).

EUROPEAN TOUR: South Africa’s Dean Burmester won the Tshwane Open for his first Tour title, closing with a 6-under 66 for a three-stroke victory at Pretoria, South Africa.

Burmester finished at 18-under-par 266 at Pretoria Country Club. Finland’s Mikko Korhonen (67) and Spain’s Jorge Campillo (68) tied for second. American Peter Uihlein (66) was another stroke back.