Dustin Johnson wins Mexico Championship and promotion to No. 1

MEXICO CITY – Dustin Johnson arrived in Mexico trying to figure out what was wrong with his swing. He left Sunday night with his 20th PGA Tour victory and his sixth World Golf Championship and questions about how far that will take him.

Over 72 holes, only two were worse than par. No one got closer to him than two shots all weekend.

Johnson overcame a sloppy start, caught a good break from behind a tree and made the rest look easy, just like when he was on top of his game two years ago. He closed with a 5-under 66 for a 21-under total and a five-shot victory over Rory McIlroy in the Mexico Championship.

"This is a big one for me, and it gives me a lot of confidence for the rest of the year," Johnson said. "I feel like the game is in good form right now."

Johnson becomes the 38th player in PGA Tour history with 20 victories.

He won on both sides of a four-week journey, which started with his victory in the Saudi International, and he will return to No. 1 in the world next week.

McIlroy did all he could, making six birdies in a seven-hole stretch on the back nine, and closed with a 67.

Johnson won the Mexico Championship for the second time in three years. He also won in 2017 when he was playing the best golf of his life, with three straight victories against the strongest fields, only to suffer a back injury when he slipped down the stairs in his rental house on the eve of the Masters.

"It's the closest I've felt to that since I got hurt two years ago," Johnson said. "I finally feel like everything is getting very close to where I was then. ... If I know I'm hitting it well and driving it good, it's going to give me a lot of confidence."

The only drama came early.

Johnson had to make an 18-foot par putt on No. 2 to avoid a two-shot swing. He had to make a 6-foot putt to salvage bogey on the next hole to keep his lead at two. McIlroy made bogey on the next hole, and then the tournament turned on two holes and two trees.

Johnson played an iron shot off the tee to the right at No. 5 and his ball settled behind a tree. He called for a ruling, and showed the official that with a shot slightly behind but toward the fairway, his right heel was on the curb of a cart path.

Not for McIlroy on Sunday. On the par-5 sixth, he sought relief when his ball was behind a tree and his foot on the cart path, and it was denied by official Mike Stewart because he had an option to play lefthanded.