Brooks Koepka survived a dramatic series of back nine wobbles to claim the US PGA Championship by just two shots from pal Dustin Johnson and etch his name in the history books.
The strapping Floridian (29), who had followed a course record of 63 with a 65 to set the lowest halfway total in major championship history, saw his tournament-record seven-stroke lead reduced to just one shot with four holes to play in tough final round conditions at Bethpage Black.
He looked to be in total control when he turned in level par by following a bogey at the first with a birdie at the fourth to lead by four shots from his close friend on 12-under par as the other players tied for second with Johnson overnight — Harold Varner III, Thailand's Jazz Janewattananond and Luke List — fell away.
But after extending his lead to six strokes when he birdied the 10th and Johnson bogeyed the 11th, Koepka bogeyed the 11th, 12th and 13th and Johnson birdied the 15th to see the lead shrink to just two strokes.
When Koepka overshot the par-the 14th and made bogey, his lead was down to just one.
But while Johnson failed with a seven-footer for par after overshooting the 490-yard 16th, then dropped another shot after going long at the 206-yard 17th to see the gap grow to three again, Koepka had to crawl over the line.
As Johnson closed with a scrambling par for a 69 to finish on six-under 274, becoming the eighth player to record runner-up finishes in all four majors, Koepka three-putted the 17th from 40 feet to go to the last with just a two-stroke lead.
He made it dramatic when he tugged his driver into deep rough, but he slashed back into the fairway and got up and down from 68 yards, holing a six footer for a four over 74 to win by two shots on eight-under par and move to world number one.
It was Koepka's fourth major victory in his last eight starts, helping him become the first player to hold back-to-back titles in two majors at the same time following his US Open wins in 2017 and 2018.
Jordan Spieth (71) was third on two-under with Matt Wallace (72) and Patrick Cantlay (71) on two-under with List (74) sixth and Sung Kang (72) seventh.
It was also a good week for the Irish with Shane Lowry thrilled to finish tied for eighth with Rory McIlroy, Gary Woodland Matt Kuchar, Erik van Rooyen and Adam Scott on one-over-as he followed an opening 75 with rounds of 69, 68 and 69.
Playing in his 25th major, the Clara man (32) found himself a shot outside the cut mark with two holes of his second round remaining but birdied the 17th and parred the last to make the weekend on the four-over limit.
He then played sensational golf over the last two days and will head home to rest and prepare for the US Open with high hopes that he can make an already excellent season even better.
"I suppose if you had told me at the start of the week I was going to shoot three rounds under par around here, I would have thought I had a chance to win," Lowry said.
"I'm obviously very happy with my week. I was lying probably 112th or 113th after round one, birdied 17 to make the cut and now I might have half a chance to sneak in a Top-10 which would be a great week and a great bit of confidence to take away for me.
"Honestly, I felt like I played great. I felt like I was so in control for the last three days. Thursday was a bit of a write-off but the last three days have just felt great.
"On Friday morning, I was on the range and I was just hitting a few, and I just found a rhythm. It was nothing to do with my swing. It was just a timing and a rhythm thing. It felt good."
After getting up and down from sand for birdie at the fourth, where he holed a 15 footer, Lowry made a 17 footer for another sand-save par at the sixth before rifling a 203-yard approach to three feet at the seventh to go two-under for the day.
A pivotal moment in his round came at the difficult 498-yard 12th, where he drove into deep trouble but got his second to within 55 yards of the pin, then pitched to 27 feet before rolling in the par putt for a par.
"I took my medicine and chipped it 30 feet left the hole because I knew a bogey wasn't going to kill me," Lowry said. "But to roll that, that gave me a serious pep in my step going to the next tee."
He couldn't get up and down from sand for par at the 149-yard 14th but he did so at tough 16th after his 220-yard three-iron found the greenside bunker on the left, making a six-footer for his four before getting up and down from greenside rough at the 18th to break 70 again.
Looking forward to getting home after a three-month stint in the US, Lowry will have two weeks off before playing the RBC Canadian Open in preparation for the US Open at Pebble Beach.
"Every part of my game feels really good at the minute," Lowry said. "You take out my first round, I probably wasn't going to be contending, but it's nice to be out there late on a Sunday and especially around here.
"I quite enjoyed today. It's quite loud out there, but I just enjoy being out there. I felt like I was in the heat of the battle today, and that was really nice."