SOUTHAMPTON, N.Y. -- Keith Mitchell's first swing in Thursday's opening round of the 126th U.S. Open resulted in a hooked tee shot that ended up in the rough at Shinnecock Hills Golf Club.
He needed four more strokes to reach the green, resulting in a double-bogey 6.
Mitchell's opening nine holes on the back nine didn't get much better, as he made bogeys on Nos. 11, 13, 14 and 16 and made the turn at 6-over 41.
What happened on the front nine after that put Mitchell in the U.S. Open record books.
Remarkably, Mitchell made birdies on three of the first holes on the front nine and then carded an eagle on the par-5 fifth. He added another birdie on the ninth to card a 6-under 29 on that half of the course.
Mitchell became the first golfer to post 29 on the front nine at Shinnecock Hills and recorded just the seventh nine-hole score of 29 in U.S. Open history. Neal Lancaster shot 29 on the back nine in the final round in 1995, according to Elias Sports Bureau.
It's the first time in the 126-year history of the U.S. Open that a golfer scored 40 or worse on one nine and better than 30 on the other in the same round, according to Justin Ray of The Athletic.
At even-par 70, Mitchell was two strokes behind early clubhouse leader Sam Stevens when the early wave of golfers finished.
It looked like Mitchell would be much further behind until his incredible turnaround.
On the par-4 first, Mitchell elected to hit driver on the 396-yard hole. He hit a 339-yard drive down the right side of the fairway, and his ball stopped 51 yards from the hole. Mitchell made a 12-foot putt for his first birdie of the round. It wouldn't be his last.
After a 338-yard drive on the par-3 third, Mitchell hit his approach to 3½ feet for birdie. He made a 10½-footer for birdie on the fourth. On the fifth, he smacked a 358-yard drive down the fairway and hit his approach from 229 yards to 13 feet to set up an eagle.
On the ninth, Mitchell made an 8½-foot putt for birdie to match the lowest nine-hole score in U.S. Open history.