The likelihood is that Thomas will not last anywhere near as long in what promises to be a turbulent summer at the summit.
Respect to the 25-year-old for his achievement – only Tiger Woods, Rory McIlroy and Jordan Spieth have done so at a younger age but it is hard to see Thomas dominating for a long period like his predecessor.
For a start Spieth, who is back up to No 3 in the rankings, is in action this week in his native Texas at the Byron Nelson Invitational desperate to put on a show for his home fans. And then there are the European challengers in the top five, Jon Rahm and Justin Rose, who will be plotting moves in the weeks ahead.
And then there are the thoroughbreds slightly further back like McIlroy and Jason Day, both former World No 1s, who are eminently capable of putting a hot streak together in a run of big tournaments and wrestling back top spot.
Since the world rankings were introduced in 1986, 21 players have held the position of World No 1 and by definition all of them have been fine players but it is longevity there which sets certain players apart.
The six who have occupied the position for more than 60 weeks – Woods (683), Greg Norman (331), Nick Faldo (97), McIlroy (95), Johnson (64) and Seve Ballesteros (61) – is a who’s who of modern greats.
Johnson is something of an interloper in such company; he was been a beneficiary of an erratic period in the world game when the last 11 Majors have been won by different players.
Thomas? Well, he does not instantly leap to mind when you think of the best golfer on the planet but the rankings reward consistency and he has not missed a cut in his 19 events since last year’s Open.
Coached by his father Mike, a PGA pro in Kentucky, he first played on the PGA Tour at the Wyndham Championship as a 16-year-old.
After a stellar college career at the University of Alabama he made his professional debut at the 2013 Alfred Dunhill Links Championship in Scotland.
His PGA Tour card came in 2014, his first win at the CIMB Classic taking him into the world’s top 50 in 2015 and a repeat win in Malaysia in 2016.
Last year brought his Major Championship breakthrough with a triumph at the USPGA.
He has pressed on this year with a win at the Honda Classic and three more top tens off the back off his punishing driving – despite his slight frame he averages 312 yards on the PGA Tour – and his uncannily accurate mid-range putting.
An 11th place finish on Sunday night at a Players’ Championship dominated by winner Webb Simpson took him to No 1.
“Being No 1 in the world is a great accomplishment but keeping that spot is more important to me,” he said. “I want to do it for a really, really long time because that means I’m playing better than everybody else for an extended period.
“It feels deserved for how I’ve played but, at the same time, if I get hot for a year or two, have it and then fall off the map, that doesn’t really mean a whole lot to me. I would much rather continue to play well for another five to ten years and see how long I can have it.”
Owning the position is a noble aspiration but one he is likely to find hard to fulfil.