Dustin Johnson replaces Jason Day as world number one with LA win

Jason Day has warned the other top golfers that they need to raise their games if they are going to keep tabs on the new world No.1 Dustin Johnson.  

The American leapfrogged the Australian at the head of the rankings, courtesy of a facile five-shot win in the Genesis Open at the Riviera Country Club in Las Vegas on Sunday night. And there were ominous words for Rory McIlroy and Co from Day, who could only finish in a tie for 64th.

"Whatever he's doing, he just needs to keep doing it," Day said. "If he keeps playing the way he’s playing, we’ve got to pick our game up and just try to compete with him."

For Johnson, himself, the mantle seems overdue, although true to his laidback image, he was more interested in the the trophy in his hands. “Winning the golf tournament - that's what I was here to do,” Johnson said. “But I do believe in myself. I think I'm a great player.”

The manner of this victory all but confirmed it. Despite having to play 36-holes on the final day due to weather suspensions, the 32-year-old was in cruise control, easily account for the Belgian Thomas Pieters and fellow American Scott Brown, with England’s Justin Rose finishing in a tie for fourth.

Rose summed up the general reaction to Johnson’s elevation. "He’s just one of those natural-born golfers," he said.

Jordan Spieth, who was world No 1 in 2015, concurred, saying this rise was inevitable after he made his major breakthrough at  the US Open last June.  "Once that happened, that was a big monkey off Dustin’s back and it freed him up," Spieth said. "He was given a hard time for a long time about close calls in majors. This is no surprise to us players, and I don't think too much of a surprise to many others.”

There can be no doubt that Johnson has endured his troubles. In 2014, he took a “voluntary” absence for six months after reports that he had twice tested positive for recreational drugs. Johnson admitted to seeking professional help for “personal issues” and was helped by his fiancee’s father, Wayne Gretzy, the ice hockey legend. Since then he has pieced his life back together. He and Paulina are expecting their second child.

"When an athlete of Wayne’s stature thinks very highly of you, it definitely gives you a lot of confidence and gives you more belief," Johnson said.

Spieth once called Johnson “a freak athlete” and the lengths this 6ft 4in, 15st specimen can launch the ball it is easy to understand why. He certainly has the talent to remain at the top. But Adam Scott, another former world No 1, does not think it will work out that way, with the likes of McIlroy in pursuit.

"Just enjoy it, because as we've seen since Tiger [Woods] really dominated that position, no one's staying there too long," Scott said. "The target’s on your back and everyone’s coming for you. There just isn’t the separation between the top players that there was during that long period of time when Tiger was far ahead."

Player profile | Dustin Johnson