OAKMONT, Pa. — All the chaos and confusion couldn’t stop Dustin Johnson from proving he had the head to be a U.S. Open champion.

One year after the most devastating of all his close calls in the major, Johnson endured two hours of not knowing the size of his lead while the USGA questioned whether he should be penalized one stroke for his ball moving on the fifth green.

Johnson said it didn’t. The USGA said it would wait until after the final round to decide.

America’s most powerful golfer took matters into his own hands Sunday at Oakmont with a 10-foot par save on the 16th hole, a tee shot he smashed down the middle of the 18th fairway and an approach to 5 feet for birdie that left no doubt who won the toughest test in golf.

Only after he was guaranteed that silver trophy did the USGA assess him a one-shot penalty, turning his final score into a 1-under 69 for a three-shot victory.

The lingering question was whether this U.S. Open was tougher than it needed to be.