Dustin Johnson won the 2016 U.S. Open on Sunday at Oakmont Country Club in Oakmont, Pennsylvania, despite having to overcome a controversial one-stroke penalty to do so.

The 31-year old Johnson, who shot a final-round 69, finished at a 4-under 69 for the tournament, good enough for a three-stroke victory over Jim Furyk, Scott Piercy, and Shane Lowry.

A native of Columbia, South Carolina, Johnson played the final six holes of the final round not really knowing what his actual score was.

The controversy dealt with Johnson moving his ball on the fifth hole as he was about to attempt a 6-foot par putt.

Johnson took two practice strokes near the ball, and then briefly set his putter down before starting to put it behind the ball.

It was then that the ball moved slightly backward, forcing Johnson to recoil.

Johnson immediately called in a rules official and explained what happened, and was told to putt the hole out, before being told on the 12th hole that he might be penalized after all.

It was later determined that Johnson grounded his club, and was indeed enforced a one-shot penalty.

Interestingly, it was a controversial ruling at the 2010 PGA Championship that cost Johnson a shot at that major championship.

In that tournament, on the final hole, Johnson grounded his club in a fairway bunker, costing him a two-shot penalty, and kept him out of a playoff between Martin Kaymer and Bubba Watson.

For Johnson, the victory marked his 10th on the  PGA Tour, and his first major championship, after several close calls, including a second place finish in the 2105 U.S. Open, as well as a second place finish in the Open Championship in 2011.

At the par-70 course, Johnson finished with rounds of 67-69-71-69 in the four-day event.