Johnson’s five-shot victory at the Riviera Country Club in California Sunday sees him rise from third to first and supplant Australia’s Jason Day who has held the top spot in the rankings since March 2016.
Reigning US Open champion Johnson finished the tournament on 17-under par following a final round of 71 to clinch the 13th PGA Tour victory of his career.
“I played really well,” American Johnson told reporters. “I wasn’t really thinking about my world ranking … I mean, I look at the world golf rankings but it’s not like my goal … I want to win the golf tournament I’m playing.
“If I get to No. 1 from winning the golf tournament obviously that’s a bonus. The most important thing is winning golf tournaments.”
Doing the maths
Johnson, 32, becomes the 20th player to achieve the top spot in golf since the rankings were introduced in 1986 but confessed to being slightly confused as to how they are calculated.
“I don’t really understand it but I can read the one, two, three — so I guess that’s all that matters,” Johnson said.
Tiger Woods holds the record for most time ranked No. 1 with 683 weeks with two-time Open champion Greg Norman a distant second with 331 weeks at the top.
Asked by a reporters what is harder to achieve: winning a US Open title or becoming world No. 1, Johnson sided with the rankings.
“To be No.1 in the world you’ve got to play very well for a long period of time where winning a major is unbelievably difficult too but you only have to play well for four days,” he said.
“So probably No.1 in the world because you’re really not going to get there without winning a major — I mean, I guess you can but it’s hard.”
Most weeks spent at No. 1 (top 10)
683 weeks — Tiger Woods (US)
331 — Greg Norman (AUS)
97 — Nick Faldo (UK)
95 — Rory McIlroy (NI)
61 — Seve Ballesteros (SPN)
56 — Luke Donald (UK)
51 — Jason Day (AUS)
50 — Ian Woosnam (UK)
44 — Nick Price (ZI)
32 — Vijay Singh (FJ)