Johnson was standing on the 13 tee at even par for the day after a bogey on 12, when he took a practice swing with his driver, and accidentally made contact with his ball that was on the tee.
Johnson inadvertently hit the ball on his practice swing, sending it caroming off the tee marker on the right.
The rule in question is Rule 6.2b 5.
After the initial shock the Englishman said Johnson saw the amusing side.
Despite his pride being hurt, Johnson did not incur a penalty and he ended up making a birdie.
According to a new rule, because there was "no intent" to hit the ball, Johnson does not receive a penalty on the hole.
"I don't think I could do it again if I even tried", Johnson said.
"I thought I had done it all, but now I have done it all", he said after his round.
"I actually hit a really good tee shot after that, so I think I recovered nicely", he said, although he noted that playing partner Matt Kuchar would likely not let him forget the gaffe.
Unfortunately for Johnson, his weekend prospects look slim after two consecutive bogeys on the final two holes of his round have left him looking very vulnerable at +3, with current leaders Francesco Molinari and Jason Day sharing the clubhouse lead at -7.