Bryson DeChambeau flagged by U.S. Open rules official after improper fairway placement noticed.

Bryson DeChambeau was left muttering ‘that was dumb’ after a tense exchange with a rules official at the U.S. Open on Thursday, with the defending champ enduring a frustrating start at Oakmont.

Bryson DeChambeau was caught up in a peculiar moment early in his opening round at the U.S. Open on Thursday, with a rules official stepping in to tell the defending champion he had made a mistake.

The LIV Golf star, who has made a decision on his future with his contract set to expire, appeared off-color at Oakmont, where the brutal conditions have dominated the build-up to the tournament. After recently making a big equipment change, DeChambeau made a sluggish start with a bogey at the first and remained at one-over-par when he arrived at the par-five fourth hole, where he piped his drive down the center of the fairway

The ball came to rest in a spectator crosswalk, a designated area where players are allowed free relief. That’s when things started to unravel. Bryson DeChambeau chose to take the relief and asked his caddie, Greg Bodine, to pick up the ball.

Bodine complied, but failed to mark the ball’s original position. When DeChambeau later changed his mind and wanted to play from the original spot, he wasn’t allowed—because the ball hadn’t been marked.

During the confusion, a USGA official stepped in and informed DeChambeau that he couldn’t return the ball to its original position without a marker, and would face a penalty if he did. He had to instead drop behind the crosswalk and play from there. Preparing to take his shot, DeChambeau muttered to his caddie, “That was dumb.”

But the issue didn’t end there. DeChambeau placed the ball on the fairway rather than properly dropping it, prompting another intervention by the official, who warned him again that a penalty would be assessed unless he corrected it.

After further discussion, DeChambeau resolved the situation, properly dropped the ball, and continued his round. He made par on that hole, followed by birdies on the fifth and seventh to move under par.

However, his momentum faltered with bogeys on the ninth, 12th, and 15th, ending the day at two over par as he neared the close of his first round in Pittsburgh.

DeChambeau came into Oakmont as one of the tournament favorites, buoyed by recent strong finishes at The Masters and PGA Championship, as well as the confidence from his U.S. Open win at Pinehurst No. 2 the previous year, where he edged out Rory McIlroy in a dramatic finale.

Speaking before the tournament, DeChambeau acknowledged the formidable challenge Oakmont presents. “I think everyone knows this is probably the toughest golf course in the world right now. You’ve got to hit fairways, hit greens, and two-putt at worst. When you get inside 10 feet, you’ve got to make those putts. It’s a great test of golf. I’m excited—and I think everyone else is too. Whoever wins this week will need to be sharp off the tee and solid on the greens.”