DeChambeau, the defending US Open champion, would struggle on the greens to eventually sign for a three-over 73, with Masters champion Rory McIlroy a further shot back. That's seven (or eight in McIlroy's case) shots off leader JJ Spaun, who was the only player in the morning group who didn't record a bogey all day.
DeChambeau was in the hunt at one under after eight holes, but things fell apart. He three-putted for a bogey on the ninth, made a mess of the par-5 12th, hit his drive on No. 15 into a bunker and carded another bogey, then had another three-putt bogey on 16.
While the American found eight of 14 fairways and 13 of 18 greens in regulation, his short game and putting plagued him throughout the round. DeChambeau needed 32 putts to get the job done on Thursday.
"For whatever reason, I just couldn't get the speed of the greens dialed," the 31-year-old told the press after the round.
"I was in the collar a couple times and had three three-putts. This golf course can come up and get you pretty quick, and you've just got to be on your game.
"And it got me, and I wasn't fully on my game, so pretty disappointed with how I played. It's not too far off, you know. Just got to get the putting a little bit more dialed, and I'll be right there, because 3 over could have easily been 2 under today."
Meanwhile, McIlroy was in excellent shape after carding a 2-under 33 on the back nine to start his opening round. But things were very different coming home. He carded bogeys on the first, fourth, sixth and seventh and settled for a double bogey on the eighth for good measure. McIlroy finished 6-over 41 on the front nine.
The Northern Irishman struggled on the fourth. After hitting his drive into the tall native grass, tt took him three shots to get his ball back into the fairway. Incredibly, he drained a 30-foot putt for a bogey.
As fans have become accustomed to, McIlroy snubbed the press at Okamont.
Fresh off leading his Crushers GC squad to a third straight LIV Golf team victory, Bryson DeChambeau has doubled down on his belief that team-based competition is the key to golf's evolution.
JJ Spaun's incredible iron shots were backed up by a solid putting performance that led to his maiden major triumph at the US Open.
World number one Scottie Scheffler and Austin Eckroat share the lead after the opening round of the Travelers Championship on Thursday.
JJ Spaun called it "a storybook, fairytale ending" to his US Open win - and it's hard to argue.
