ERIN, WIS. — Brooks Koepka had just tapped in a 20-inch putt to become the 117th U.S. Open champion, and he gave the moment a low-grade golf fist pump. Twice. That was it.

The celebration was about as muted as you’ll ever see from someone who just won their first major. His performance was anything but.

It capped a week in which the biggest names vanished after two rounds, leaving the leaderboard a collection of rarely seen names. And, boy, there were a lot of them.

But in the end, a four-hole stretch of par and three birdies made Koepka a household name. This U.S. Open wasn’t lost; it was won by a 27-year-old Florida native who had only won one other PGA tournament.

“That’s probably one of the coolest things I’ve ever experienced, and to do it on Father’s Day, it’s pretty neat,” Koepka said. “I didn’t exactly get my dad a card, so this works.”

Koepka shot a 67 on his winning round. He had six birdies and one bogey in an exhibition of steady play. He shot under par in all four rounds at Erin Hills.

The margin of victory was four strokes and the winning total was 16-under. Hideki Matsuyama, who shot a sizzling 66, and Brian Harman, the third-round leader, finished at 12-under. Tommy Fleetwood was 11-under, and Xander Schauffele, Bill Haas and Rickie Fowler were one more stroke back.

Koepka was mostly unknown to the casual golf watcher, but his athletic build and solid form have made him a favorite of those looking for the next star of their fantasy golf league. Entering Sunday, his only PGA Tour victory was in the 2015 Waste Management Open in Phoenix. But he’s been close a lot.

His previous best U.S. Open finish was a tie for fourth in 2014.

If you live in Jupiter, Fla., and you were taking one of those childhood tests to figure out which item doesn’t belong, Koepka would have been that item when talking about the community’s pro golfers.

The city is home to defending U.S. Open champion Dustin Johnson, Rory McIlroy, Rickie Fowler and, of course, Tiger Woods. Koepka and Johnson even train and hang out together. Now he truly belongs.

Johnson, who didn’t make the cut, called Koepka on Saturday night.

“It wasn’t a long phone call,” Koepka said. “It was like two minutes, it wasn’t much. But he just said a few things, to just stay patient. And I’ll win if I stay patient and just keep doing what I’m doing.”

The stretch in which Koepka won this tournament started on the 13th hole. He was tied with Harman. His tee shot on the par three ended up rolling off the green and down a slope. He had about 78 feet, mostly uphill, to reach the pin. He came to about 9 feet with his second shot. He made the putt.

“That par save was massive on 13,” Koepka said. “That’s the reason I had so much confidence coming down, especially with the par five coming up, knowing that I needed to birdie that.”

Koepka got in trouble again on the par-five 14th when he put his second shot in a bunker. But a brilliant sand shot put the ball to about 4 feet for birdie. He made the putt.

“Leaving that in the bunker wasn’t that bad,” he said. “Anywhere over there was fine.”

Actually, all he had to do was par out and he would probably win the tournament. He had a two-shot lead over Matsuyama, who was in the clubhouse.

But on 15, which was the toughest playing hole on the course Sunday, he put his approach about 10 feet away for birdie. He made the putt.

And on 16, a par three, he put his tee shot 17 feet away for his third birdie in a row. He made the putt.

He had a four-shot lead with two holes to play. He parred them both.

“I played really solid from the moment we got here on Monday and all the way through [Sunday],” Koepka said. “The ball-striking was pretty solid. It had to be, especially with the wind. And I got out there with the putter a little bit [Sunday] and all week. So all around my game is pretty solid and I couldn’t be happier.”

Harman, who was playing in the final group of the day just behind Koepka, had lost all of his energy as he approached the 18th hole, where a par would have given him sole possession of second place. He bogeyed the hole.

“It bites a little bit right now,” Harman said. “But Brooks played so well today. The conditions were so tough. So you’re in the next to last group and you shoot the [second] lowest round of the day, that’s tough. That’s tough.”

Matsuyama had the round of the day, a six-under 66. He had eight birdies and two bogeys.

“We watched the finish in the clubhouse on TV,” Matsuyama said. “Brooks is a good friend of ours and we’re happy for him. Wish him well and congratulate him. I’ll try and beat him next time.”

Fowler birdied the first hole but could get little going beyond that. His even-par 72 left him in a familiar spot, in search of his first major championship.

Yet Fowler remained Mr. Positive.

“I feel like I’m playing at the highest level,” Fowler said. “If you look at the negatives too much, I mean, you’re going to be stuck doing that the whole time. You have to measure success in different ways, not just by winning, because that doesn’t happen a whole lot.”

Fowler finished tied for 11th at the Masters and seemed satisfied with his 10-under at Erin Hills.

“Even though the scores were somewhat lower than a normal U.S. Open, to finish in double digits under par at a major championship, especially the Open, it was a good week.”

The U.S. Open returns to one of its more traditional courses next year when it goes back to Shinnecock Hills in Southampton, N.Y.

Koepka won’t be anonymous. There will be expectations. But his resume will be looking a whole lot better than this year.

john.cherwa@latimes.com

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