And so it proved as he came from seven shots back to force a play-off and win the second Major of his career.
His record-equalling feat, which matched that of John Mahaffey in coming from seven off the pace to win the PGA in 1978, was helped by a dramatic late implosion from Mito Pereira.
In only his second Major, the Chilean just needed par on the 18th to take an unlikely win but found the water, double-bogeyed the hole and didn’t even have the chance of the play-off to make amends.
Instead, it was a straight head-to-head over three holes between Thomas and his fellow American Will Zalatoris. Over a return to the 13th, 17th and 18th, Thomas was just one stroke better than Zalatoris for the Wanamaker Trophy.
“It’s funny, I was asked earlier in the week about what lead is safe and I said ‘no lead’,” Thomas said following the win. “This place is so tough. But if you hit the fairways you can make birdies and I stayed so patient, I just couldn’t believe I found myself in a play-off.”
The 29-year-old credited his caddie Jim ‘Bones’ Mackay for the win, which seemed apt off the back of the build-up to the tournament. He had been the bagman for most of the career of Phil Mickelson, last year’s champion who was the talk of the event for his no-show and plans to participate in the divisive LIV Golf Series next month.
“It was a bizarre day,” added Thomas. “Bones did an unbelievable job of just keeping me in the moment. We just tried to play the golf course for what it is.”
For his part, Pereira was sanguine about the manner of his late capitulation, admitting the occasion had simply got the better of him. “Today, I was really nervous,” he said. “I tried to handle it but it was really tough. I thought I was going to win on 18 but it is what it is. We’ll have another one.”
Hopes of a first English winner at the event for more than 100 years evaporated as Matt Fitzpatrick, playing in the final group three shots off Pereira’s lead, faded with a final-round 73. “It’s tough to take but I just didn’t hit the ball very well,” was his honest summary.
Rory McIlroy threatened to have one of his final-day surges after four birdies in quick succession, but lost his momentum and his 68 left him in eighth place.
Tommy Fleetwood went one better with a 67 to tie with Fitzpatrick on three-under, following on from ending up 14th at the Masters.