Wild final round at the U.S. Open

OAKMONT, Pa. -- Dustin Johnson's path to winning his first major has not been easy. So many opportunities without a single conversion. So much heartbreak.

A cloud of uncertainty hanging over his head Sunday afternoon at Oakmont made it even more difficult, as he played the majority of the back nine facing the possibility of a penalty stroke.

But in the end, Johnson finally claimed that elusive major in a gutsy, gritty performance at the U.S. Open.

"Best Father's Day ever," said Johnson as he stood by his fiance Paulina Gretzky and their son Tatum.

When asked how it felt to have his family there, he replied, "It means the world. It's Father's Day. My birthday's in a couple days. Couldn't have came at a better time."

Johnson walked off the 18th green not knowing his exact score but knowing he had survived a tense and unusual final round. Jack Nicklaus, also a U.S. Open winner at Oakmont, was among those who waited to greet him.

He walked into the scoring area with a 2-under 68 on his final round and a four-shot lead. He was assessed a one-stroke penalty for causing his ball to move on the putting green on the 5th hole, resulting in a 1-under 69 and a total of 4 under.

"He accepted the penalty and included it on his scorecard," said the USGA's Jeff Hall, "and that was the end of the conversation."

The lost stroke didn't matter. All that matters is he finally emerged on a Sunday of a major.

"Feels good. Feels really good. Fell well deserved. I've had a lot of opportunites that I didn't quite get it done. So this one's definitely really sweet."

Johnson has a history of 18th hole disappoints in major tournaments, beginning with the PGA Championship at Whistling Straits in 2010 when he was penalized a shot on the last hole for grounding his club in a hazard.

A year ago, Johnson had a 12-foot eagle putt to win at Chambers Bay but instead three-putted to lose to Jordan Spieth by a stroke.

This time, he striped his drive down the 18th fairway, then hit a magnficent approach to within 4 feet, rolling in the putt for a birdie. Even before he reached the final green, playing partner Lee Westwood shook Johnson's hand.

"Might have been one of the best shots I ever hit, especially under the circumstances," Johnson said of his approach shot.

The controversial afternoon stemmed from a situation on the fifth hole.

Johnson was standing over a 6-foot putt for par on the 390-yard par 4 when the ball appeared to move ever so slightly. Johnson was taking a few practice strokes behind the ball when it moved just a touch. It moved again just as Johnson moved the putter behind the ball to hit.

Johnson stepped away from the ball and asked for a ruling. He then made the putt and moved on to the next hole.

There was no immediate penalty given to Johnson, though USGA officials told him they wanted him to take a look at the tape after the round.

He was then met by rules officials on the 12th tee and asked if there was something else that could have caused the ball to move. His response was not sufficient for the officials and was then told there was a possibility of a one-stroke penalty.

Johnson played the back nine in even par, able to manage the looming penalty.

He had started the round four strokes behind 54-hole leader Shane Lowry. But while Johnson went out in 1 under, Lowry was 4 over on his round at the turn, making them tied going into the back nine.

Lowry continued to struggle, making three consecutive bogeys to take himself out of contention.

He eventually finished in a tie for second with Jim Furyk and Scott Piercy at 1 under.

Sergio Garcia and Branden Grace shared fifth at even par.