Justin Thomas produced one of the greatest final-round fightbacks in Majors history to win his second US PGA Championship.
Thomas, the World No. 9, won a three-hole playoff against fellow American Will Zalatoris after both had finished at 5-under 275 although that doesn't begin to tell the whole story of a dramatic denouement.
The 29-year-old, who started Sunday seven shots back from leader Mito Pereira, arrived in a playoff after carding a final-round 3-under 67 in tough conditions at Southern Hills in Tulsa.
Despite playing his last 10 holes in 4-under, it looked as if Thomas's late charge wasn't going to be enough.
But leader Mito Pereira left his birdie try at 17 hanging on the lip to stay at 6-under and, teeing off at the last with a one-shot advantage, the Chilean took a disastrous double bogey-6 after finding water with his low drive and didn't even make the playoff.
Zalatoris wriggled in an eight-footer at 18 to complete a 71 and match Thomas's 5-under total while he birdied the first hole of the three-hole playoff.
However, Thomas matched that four on the par-5 13th after getting up and down from distance and added another birdie at 17.
When Zalatoris couldn't birdie 18, Thomas had two putts for the championship and he took them to win the Wanamaker trophy for the second time and secure his second Major title, his first since 2017.
By rallying from seven behind, Thomas matched the biggest comeback in US PGA Championship history, John Mahaffey also overcoming a seven-shot final round deficit in 1978.
Pereira (5-over 75), who started Sunday with a three-shot lead, finished third alongside Cameron Young (71) while playing partner Matt Fitzpatrick (73) had to settle for tied fifth alongside fellow Englishman Tommy Fleetwood (67) and American Chris Kirk (68).
A disappointed Rory McIlroy refused to talk to any press after finishing three shots back on 2-under.
The Northern Irishman had made a sparkling start with four straight birdies from Nos. 2-5 getting him to 4-under (one back from the eventual play-off number) but he played the rest of his round in 2-over to slip to eighth.
What they said
Although McIlroy didn't choose to offer his post-tournament thoughts, Pereira won much praise for talking to multiple media outlets after his agonising double bogey finish.
"A lot of self-belief, a lot of patience. I wasn't looking at leaderboards today. I was just trying to play golf. It kind of goes back to what I said on Thursday of just not trying to play golf swing, not trying to play the field, not trying to play to a certain person really.
"Just trying to execute each shot as well as I could, and then wherever it ended up, just give my club to [caddie] 'Bones' and let's move on and try to do the best we can on the next one. He did an unbelievable job of keeping me in the moment and keeping me patient today, and yeah, it just is an unbelievable team win for all of us.
"It was a bizarre day. I definitely crossed one off the list, and I've never won a tournament shanking a ball on Sunday, so that was a first, and man, I would really like it to be a last.
"It's funny, I was asked earlier in the week about what lead is safe, and I said, no lead. 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 playoff."
"I didn't have my best stuff yesterday, which ultimately was kind of the difference.
"I battled like crazy today, especially after on 6 where you caught a random gust downwind and having to save a bogey off the cart path. I'm close and I'm super motivated, but we'll get one soon. Pretty proud of the result that I had."
"Obviously sad to be here and not in the playoff, not make par, just straight win.
"On 18, I wasn't even thinking about the water. I just wanted to put it in play, and I guess I aimed too far right. I just hit in the water.
"It's not how I wanted to end up this week, but really good result. Played really good. Today I was really nervous. I tried to handle it a little bit but it's really tough. I thought I was going to win on 18, but it is what it is. We'll have another one."
"We had a good time for the most part. Yeah, it's always a hard day. It's Major championship golf. It was clearly very difficult today.
"I think we hung in there pretty well for a long time, and unfortunate to have a couple slip away at the end. But it happens when you're right around the lead."
"It's tough obviously to take. Just didn't hit very well. Wasn't a good day.
"I shoot level par today and I win it outright. If someone had said that before the round, I'd have fully prepared myself to do that. You know your target and get it around. It wasn't the day that I wanted, and it is what it is unfortunately."
Winning form gives Thomas the edge
This was a highly unusual Major in the fact that so many of the leading protagonists had never even won on the PGA Tour before.
Thomas now has 15 PGA Tour wins, including two Majors, following his dramatic victory.
But runner-up Zalatoris, Pereira, Young and Fitzpatrick are still seeking a first PGA Tour win.
All that quartet made costly mistakes in round four, perhaps showing their lack of experience.
Pereira's was the most obvious but Young had hit 6-under (what would have been the winning total) before bogeying the 14th and adding a double at 16.
Had Fitzpatrick birdied the short par-4 17th instead of bogeyed it, he would have landed on the playoff number.
And Zalatoris, who now has two second places in the Majors, missed a four-foot par putt at 16 that ultimately cost him.
That said, some of the biggest regrets were held by McIlroy, a four-time Major winner.
He had reached 5-under on day one. Had he played the rest of the tournament in just 1-under that would have been enough to end his eight-year wait for a fifth Major.
READ MORE: Rory McIlroy's long-term Major drought