MAMARONECK, N.Y. — The momentum Bryson DeChambeau built through his auspicious youth and his golf-geek precision and his gym-dude muscle and his adamant toil found its way to quite an apex Sunday. The central Californian smothered the 120th U.S. Open even at snarling Winged Foot, became golf’s latest sub-30 major winner at barely 27 and signaled that his heavy drives and fluffy touch could stoke common chatter for another decade or two.

The best evidence that his prowess can reach into the clouds came beneath so few of them. An autumnal day 25 miles northeast of Manhattan in an event postponed from June served as a backdrop for the validation of a top-10 mainstay ranked No. 9 in the world and renowned for the backbone to veer from orthodoxy. Sixty-one men awakened with the chance to go out and let the course hurl them around like talented detritus. Sixty shot black numbers.

One shot in the red.

“As difficult as this golf course was presented, I played it beautifully,” he said, calling it “validation through science” and saying, “So many times I relied on science, and it worked every time.”

With his wow of a 67 and his 6-under-par 274 shouting his major-Sunday chops to go with all his other chops, DeChambeau bested playing partner Matthew Wolff by six shots after trailing the 21-year-old front-runner by two at their midday outset. He won while hitting 23 of the week’s 56 fairways, a redefinition of ancient U.S. Open protocol.

“I don’t really know what to say, because that’s just the complete opposite of what you think a U.S. Open champion does,” said four-time major winner Rory McIlroy, age 31.

“Playing his own little golf course at the moment,” went the clause of 2010 British Open champion and longtime major contender Louis Oosthuizen, age 37.

“It’s just very different but also very, very effective. So hat’s off,” said two-time major winner Zach Johnson, age 44.

“It’s not about hitting fairways,” said constant major contender Xander Schauffele, age 26.

It’s not?

“It’s about hitting on the correct side of the hole and hitting it far so you can hit a wedge instead of a 6-iron out of the rough.”

So it must be.

A busy-brained physics major from SMU became only the third man to shoot under par in the six U.S. Opens held at Winged Foot, following only Fuzzy Zoeller and Greg Norman in 1984. He became a major winner so soon after his vow last fall — and follow-through thereafter — to transform himself into a 235-pound suggestion of a Division III football linebacker. And in the category of golf’s boundless arcana, DeChambeau, the 2015 NCAA and U.S. Amateur champion, joined only Jack Nicklaus and Tiger Woods in winning those and then a U.S. Open to boot.

He did all of the above after working on the range well into the chilly Saturday night — “My driver was not performing the way I wanted it to,” he said — and he did so with a round that should rank among the transcendent in this young golfing century, given its superiority to those of his adept rivals.

Everybody else who woke up Sunday with a chance — from third-round leader Wolff to Oosthuizen to Schauffele to McIlroy to unlucky Georgian Harris English — wound up in the leader board distance sooner or later. English did so right away from five shots off the lead, when his drive off No. 1 went both left and undiscovered in the piggish rough, a fate that wouldn’t have happened had clumsy galleries been around to find it and maybe even spill a visible sheen of a beverage upon it.

He went back to the tee, restarted his double bogey and grimaced, and when he chipped out from the sand and the depths into the hole on No. 2, it qualified as a karmic fairness. “Hitting the ball in the rough out here and trying to get it on the green is really hard,” English said, “and it’s really impressive what [DeChambeau’s] doing.”

Then the round turned for real near its turn.

Mid-round, Schauffele and Oosthuizen still had rational hope, lurking at even par with DeChambeau at 3 under and Wolff at 2 under after the leaders both bogeyed No. 8. (That was DeChambeau’s lone bogey.) Then DeChambeau skied a 375-yard picture of a 21st-century drive to the right side of the No. 9 fairway. Then Wolff bombarded a 388-yard burner just by DeChambeau. Then both sauntered onto the green of the par-5 in two. Then both did things an audience would have relished.

First DeChambeau sent a 38-foot eagle putt with some of the best pace in the wretched human history of putting. It went in without hesitation or hurry, and he led by three. “My putting was immaculate,” he said two days after calling his iron play “impeccable,” then continued: “My speed control, incredible. That’s why we worked so hard on my speed control. You see me out there on the greens with the device trying to control my speed.” Then Wolff, whose first two major finishes of his life have gone “T4” and “2,” drained his 10-footer sans drama and dramatically drew within one.

“I battled hard,” said Wolff, the Southern Californian who shot 75 while hitting seven fairways one day after shooting 65 while hitting two. “But first U.S. Open, second place is something to be proud of and hold your head up high for.”

The difference became DeChambeau’s maintenance of his steadiness. He parred the par-3 No. 10 with a formulaic two-putt, while Wolff bogeyed it after choking up half the club to exit some churlish foliage between the sand and green. Then while Wolff parred the 365-yard No. 11, DeChambeau airmailed a drive 320, sent a second shot a disappointing 13 feet shy and hit a birdie putt a not-disappointing 13 feet into the cup. The lead reached three.

Wolff bogeyed No. 14 and double-bogeyed No. 16 as his troubles began to widen and deepen. DeChambeau had made an authoritative nine-foot par save on No. 14. The lead reached six.

By the time they reached the vaunted closing Winged Foot holes that so famously felled Phil Mickelson in 2006, competition had become coronation, DeChambeau’s seventh and biggest tour win up ahead. “I’m just trying to figure out this very complex, multi-variable game and multidimensional game as well,” he said, soon adding, “I hope that inspires people to say, ‘Hey, look, maybe there is a different way to do it.’ ”

After all, he had mastered a slew of variables.

Read more on golf: