Thomas won with a score of two under after the three playoff holes with compatriot Will Zalatoris at the Southern Hills Country Club in Tulsa, Oklahoma.
The 29-year-old finished his round with a shot behind then-leader Mito Pereira, but after the Chilean slammed his drive on the 18th hole into the water and ended with a double bogey, the major moved on to a playoff between the two compatriots.
And after three holes, Thomas finished with his second big win when he won the famous Wanamaker Trophy for the second time, having won it previously in 2017.
With Thomas’ excellent play and the dramatic end when Pereira lost his advantage resulting in a play-off, Thomas summed it up as a ‘weird day’.
“I definitely took one off the list. I’ve never won a tournament with a ball on Sunday, so that was the first and I’d really like it to be the last,” he explained.
“Bones (Thomas’ caddy, Jim ‘Bones’ Mackay) did an incredible job of keeping me in the moment and just trying to play the course for what it is.
“This place is so hard. It was funny that earlier in the week I was asked what lead is safe and I said ‘no lead’ because this place is so hard. But if you hit the fairways you can make birdies and I stayed so patient. I couldn’t believe I found myself in a play-off.”
On the biggest stage
Thomas is one of the biggest names in golf.
Although he came on the scene a few years ago with 15 PGA Tour wins to his name, including his 2017 PGA Championship win, he has not won an event since the Players Championship in March 2021.
But in recent months there have been glimpses of him returning to a place close to his best.
He finished eighth at the Masters earlier this year and arrived in Oklahoma as one of the favorites for the title.
Back-to-back rounds of three-under-par on Thursday and Friday put him near the top of the standings, but a four-over-par showing in test conditions on Saturday dented his title burden.
But he arrived on Championship Sunday with a vengeance.
Again he shot a brilliant three-under 67 to put himself in the fray at five-under for the tournament. When he finished his lap, he was one shot behind then-leader Mito Pereira.
On the last hole, however, disaster struck for Pereira. The Chilean led through a shot and hit his ball into the water, eventually finishing with a double bogey at four-under.
That catastrophic mistake forced a three-hole playoff between the two Americans. And under the low Oklahoma sun, the two battled.
On the first playoff hole, the par-five 13th hole, things couldn’t have gone much better for either of them. After some nice iron shots and some solid putts, both carded birdies.
It was on the par-four 17th when Thomas’ first bit of genius gave him an edge.
A huge, thumping drive through the clear blue sky had his ball on the green, giving him two putts for a birdie. Zalatoris could only keep a par.
When asked about that drive on the playoff’s 17th hole, he called it a “nice one.”
“With the wind coming from the left, the three wood is not my favorite so I hit a great shot in regulation the way I wanted and I hit essentially the same shot with a little more edge to it,” he said
“It was fun and it put Will (Zalatoris) on edge. I love these 17th holes in PGA Championships, so I’d like to keep making that a habit.”
Thomas had a one-shot lead.
And on the par-four 18th hole, the final playoff hole, some calm and controlled golf from the world’s No. 9 tapped into a very close putt for par to round out the second major of his career.
As his father Mike stood by and the two hugged on the 18th green, the emotions of the moment finally caught up with Thomas, now a two-time major winner.
He becomes only the sixth player since World War II to have 15 PGA Tour wins, including two majors before turning 30, along with Jack Nicklaus, Tiger Woods, Rory McIlroy, Tom Watson and Johnny Miller.
Thomas’s massive comeback to claim victory trumps the biggest seven-shot comeback in PGA Championship history made by John Mahaffey in 1978.