Koepka finished four shots clear of Hideki Matsuyama and Brian Harman to capture his maiden major title, but while the margin might appear comfortable, the result only really became a fait accompli over the final few holes as, initially, Harman and later Matsuyama mounted charges.
Not only is it a win for American golf, Europe can take some credit for the victory as it was in Europe where Koepka’s professional career evolved after playing the Challenge Tour there in 2012 and 2013 and briefly the European Tour in the latter half of 2013 after three wins on the Challenge Tour before joining the PGA Tour in 2014.
It may well have been that international experience on the range of golf courses that European golf offers that allowed him the skills and confidence to handle the unique nature of the Erin Hills layout although his capacity to eventually win a major championship has never really been in doubt.
Koepka quickly announced his intentions on Sunday with birdies at his opening two holes to open up a one shot lead over Harman and Tommy Fleetwood and although joined in the lead by Harman on two occasions, he was never headed.
When Harman dropped shots at the 12th and 13th holes however, it appeared Matsuyama might be the man to challenge Koepka.
Matsuyama had birdied three of his first five holes to get to the edge of contention but when the Japanese star failed to get up and down from the front of the par-three sixth green, it appeared he might have lost the momentum he needed.
Matsuyama is an unflappable character however and birdied the 11th, 12th, 14th and 16th holes and although there was a bogey at the 15th, he came to the 18th and hit the most exquisite of pitches to move just two behind and alone in second position.
Both Koepka and Harman still had several holes to play, although that offered both opportunity and danger for both. Koepka responded to the challenge in the most positive of ways with birdies at the 14th, 15th and 16th holes to move four clear and when Harman birdied the 16th, he was just three back and, given the dangers of the closing holes, was still a challenger.
Any possible blunder by Koepka was eliminated by a two-putt par at the 17th and when he hit the longest tee shot of anyone at the 18th with, almost unbelievably, a three-wood he had the title in hand and only a holed second from Harman at the last could change the US Open title’s destiny.
It was not to be and Koepka had won just his second PGA Tour title but what a title it is.
Harman would eventually bogey the last to share second with Matsuyama.
"Just keep doing what I was doing," said Koepka when asked what his plan had been for the day.
"I felt like I was playing really good. Obviously the wind picked up and I felt like that played right in my hand. Good ball-striker, good putter. And I felt confident all week. So to feel as confident as I did on a Sunday of a major and coming down the stretch was pretty neat.
“This is a real team effort between my caddie Rickie, Claude Harmon my coach, my agent Blake, Peter Cowan, Jeff Pearce and even my trainer Joey so it is definitely a special moment."
A phone call from the defending champion Dustin Johnson, who missed the cut, was a source of inspiration and comfort to the winner.
“It meant a lot. He told me to just keep doing what you are doing and not to get ahead of myself and that I am going to win.
"It hasn't sunk in, obviously, yet, and probably won't for a few days. That's probably one of the coolest things I've ever experienced and to do it on Father's Day it's pretty neat. I didn't exactly get my dad a card, so this works (laughter.)"
Matsuyama was on the verge of creating his own history himself by becoming the first Japanese male golfer to win a major.
“I played really well today,” said Matsuyama. “I came up a little bit short. No regrets, but I did play well.
“We watched the finish in the clubhouse on TV. Brooks is a good friend of ours, and happy for him. Wish him well and congratulate him. I'll try to beat him the next time.
“If I learned anything, you've got to put four good rounds together. I played two good rounds, but it wasn't enough.
“Hopefully, though, in the future, in majors, I can play in the either last or next to last group to give myself a better chance. But I'm happy with the way I played, and it gives me confidence going forward.”
Harman echoed the thoughts of many on the venue.
“I think it's a great test,” said Harman. “If the wind was up like this all week, your winning score is much higher than it would have been. And the scores were low because the greens were good. The greens were a pleasure to putt on, and it was easy to make putts. That's why the scores are low.
“You can't make the course long enough where guys aren't going to shoot under par. If you want guys to shoot over par, you bring in the fairways, you make the rough deeper, and you make it more penal around the green. But this place is a fair test.”
Tommy Fleetwood impressed with his performance to finish alone in 4th position moving within one of the lead when he birdied the second hole.
Marc Leishman was the only Australian to make the cut but after being in contention early in the third round, he would eventually finish in a share of 27th after a final round of 75.
More on Leishman’s week can be read here.
BROOKS KOEPKA WINS 2017 US OPEN
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