Brooks Koepka ran off birdies at Nos. 14, 15 and 16 to pull away from the field at the U.S. Open and claim his first major title. (Gregory Shamus/Getty Images)

Brooks Koepka, a strapping Floridian with wowing golf talent, a chilled disposition, an athlete’s cocksure gait and a three-year place at the fringe of the bright lights, fled that fringe on a blustery Sunday at Erin Hills. He became both a 27-year-old U.S. Open champion and the latest of golf’s enviably young headliners. He did it by using an unusual amount of oomph to separate from an unusually crowded crowd.

Asked whether it had sunk in, he said, “Uh, no.”

When he approached No. 14 with his wee one-shot lead and his opinion that his wins in Japan, Turkey and Phoenix constituted underachievement, he seemed to stand far from his gorgeous 67, his four-shot win, his blissful score of 272 and a U.S. Open-record-tying score against par of 16 under. It had been just three years since he snared his PGA Tour card with a fourth-place finish at the U.S. Open at Pinehurst in North Carolina, just five since a shortcoming at PGA Tour qualifying school sent him scurrying to the second-tier Challenge Tour in Europe. And here, he proved such a trembling mess that he birdied No. 14, birdied No. 15, birdied No. 16 and sprinted from the others.

The others included recent Wells Fargo winner Brian Harman, who led Koepka by one as Sunday began and took a winding way to a 72 and 12 under; the fourth-ranked player in the world, Hideki Matsuyama, whose 66 carried him from 14th place to second at 12 under ; and neophyte Tommy Fleetwood, an Englishman who had played seven previous majors and missed six cuts and whose 72 left him at 11 under.

The others also included viable contenders who failed to menace such as first-round leader Rickie Fowler, whose 72 left him at 10 under, and third-round sensation Justin Thomas, whose record 9-under 63 on Saturday zinged with nine birdies and an eagle but whose 75 on Sunday left him at 8 under. Even in a tournament in which seven players shot double-digit numbers under par — five more than had done it in the first 116 U.S. Opens — and 31 shot under par, the whole horde of them somehow wound up looking up at one.

“He birdied 14, 15 and 16, and that was kind of lights out,” Harman said.

“I felt he’s been very unnoticed and maybe not respected as much as he should have,” Thomas said.

“You’ve got to tip your cap; he went and won the tournament on the back nine,” Harman said.

“He’s proven for a long time how good he is; now he’s done it in a major,” playing partner Fleetwood said.

He bolted up, and suspense bolted out. He took the starch right out of a heavily contended major, “and to be honest with you,” he said, “this week I don’t think I ever got nervous, not at one point. I just stayed in the moment.” Seconded his caddie, the Northern Irishman and American dual citizen Ricky Elliott, “To be honest, he was just so in control all day. He just dead-lined all day.”

As the second straight U.S. Open winner with a laconic pulse, he even talked by phone Saturday night to the first, Dustin Johnson, who had missed the cut here. “It was a long phone call,” he deadpanned. “For us, it was like two minutes.”

In the eternally odd physics of golf, he thought he had been trying too hard to win, so he won by not trying so hard to win. “There’s something about majors where I just focus in a lot more,” he said, and the record does show this: 15 majors so far, five top-10 finishes, four top-five finishes and a major, the seventh consecutive golf major to go to a first-time winner in this populous era.

To him, Sunday turned for good not so long after No. 10, where he had produced both his lone three-putt of the week and, as he assessed it, “one of the worst strokes I hit all week.” By No. 13, he faced an inconvenient nine-footer just to hang on to par. He saw the hole “in a little swale” where he played it “just outside the cup,” hit it “just high, a little bit outside.” It plunked down with flawless obedience, and Koepka said, “That par save was massive on 13. That’s the reason I felt I had so much confidence coming down.”

Coming down, he had his 3-wood from 300 at the par-5 No. 14, his 8-iron from 155 on the par-4 No. 15, and his 9-iron to the par-3 No. 16, all struck with the poise of someone who expected to be there. That posture went all the way to the understated double-fist pump at No. 18, after his two-foot par closed it with Harman and Thomas still on the course.

Pretty soon, two-time winner Curtis Strange was handing him the trophy, and Elliott, the caddie, was saying of Koepka, “I think he’ll even smile.” Merely four years ago before the PGA Championship in Rochester, N.Y., somebody had told Elliott of a young player who needed a caddie who could ply both sides of the Atlantic Ocean. Now Elliott told of watching Koepka hit roughly two beautifully struck shots with their beautifully controlled spin and thinking, “This boy’s going to be good.”