DeChambeau carded a closing 67 to finish six under par at Winged Foot, a record winning score by two shots at a revered venue where only two players had finished in red figures in five previous US Opens.
The 27-year-old was the only player to break par on a demanding final day and the only one not to shoot over par in any round.
He finished six shots clear of compatriot Matthew Wolff, who began the day with a two-stroke advantage but faded to a closing 75.
Former Open champion Louis Oosthuizen was two shots further back in third, with Harris English recovering from losing a ball from his opening shot of the day to finish another stroke back in fourth.
DeChambeau’s physical transformation has been the main talking point since golf’s return to action following the coronavirus shutdown, the American putting on 20lbs of muscle to become one of the game’s biggest hitters.
Tweet of the day
— Thomas Bjørn (@thomasbjorngolf) September 20, 2020
Former Ryder Cup captain Thomas Bjorn pays tribute to DeChambeau’s potentially game-changing win.
Quote of the day
"It's kind of hard to really wrap my head around it." @McIlroyRory reacts to DeChambeau winning despite hitting just 23 fairways at Winged Foot
— Phil Casey (@pcaseysafc) September 20, 2020
Rory McIlroy echoes the sentiments of many.
Shot of the day
— U.S. Open (USGA) (@usopengolf) September 20, 2020
With Wolff much closer, DeChambeau holed from 35 feet for a crucial eagle on the par-five ninth.
Round of the day
Winged Foot's only weakness: Bryson DeChambeau
The only player under par and he was 6-under. 😳 pic.twitter.com/9CwnFqjuuw
— PGA TOUR (@PGATOUR) September 20, 2020
DeChambeau was the only player in the field to break par on the final day.
Statistic of the day
Bryson is the fourth player since 1900 to win the U.S. Open by 6 or more strokes for his first major victory:
1902 Laurie Auchterlonie
1906 Alex Smith
2011 Rory McIlroy
2020 Bryson DeChambeau
— Justin Ray (@JustinRayGolf) September 20, 2020
DeChambeau’s six-shot win places him in some elite company.
For the fourth day in a row, the par-five ninth was the easiest hole, playing to an average of 4.508 and yielding four eagles and 26 birdies.
The par-four first hole played to a higher average than the ninth, 15 bogeys and 10 double bogeys contributing to an average of 4.557.
On the up
Sales of single-length irons and protein powder after DeChambeau’s unique body-building approach paid off.
On the slide
Respect for the USGA’s slow-play policy after the final pair took almost four and a half hours to complete the final round without facing any threat of sanction.