Shane Lowry slips up as Dustin Johnston wins farcical US Open

Dustin Johnson survived a farcical climax to the US Open to win his first major title as Offaly's Shane Lowry let slip a four-shot lead at Oakmont.

Johnson carded a closing 69 to finish four under par, but only after belatedly being given a one-shot penalty following an incident which left players, officials and spectators unsure of his score with just seven holes to play.

The world number six began the final round four shots behind Lowry, but moved two clear of the field with birdies on the second and ninth coupled with four bogeys in the first 10 holes from Lowry.

However, the 31-year-old was then told on the 12th tee that officials would be reviewing an incident on the fifth hole, bringing back memories of his nightmare finish to the 2010 US PGA when a two-shot penalty for grounding his club in a bunker on the 72nd hole cost him a place in the play-off.

Lauren Coughlin holds first-round lead at the Chevron Championship

Scottie Scheffler out to win at Hilton Head after clinching second Masters title

Johnson had seen his ball move fractionally as he lined up a par putt, but called in the referee walking with his group and was initially cleared of any wrongdoing before holing out for par.

The news that Johnson had been informed of the post-round review was widely criticised, with four-time major winner Rory McIlroy writing on Twitter: "This is ridiculous... No penalty whatsoever for DJ. Let the guy play without this crap in his head. Amateur hour from USGA."

And defending champion Jordan Spieth added: "Lemme get this straight.. DJ doesn't address it. It's ruled that he didn't cause it to move. Now you tell him he may have? Now? This a joke?"

Johnson was eventually given a one-shot penalty but still finished three shots clear of Lowry - who struggled to a disappointing 76 - Scott Piercy and former champion Jim Furyk.

Asked how he coped with the uncertainty of the situation, Johnson said: "I knew I was swinging well and I just kept thinking it's just me and the course. I'm playing against the course. I can't control what anyone else does.

"So I just tried to hit golf shots, tried to hit it on the correct side of the hole and two-putt.

"I hit two great shots on 18. It might be one of the best (approach) shots I ever hit. So that was very nice to have a short putt like that to get it in the house.

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

The 31-year-old enjoyed an enormous stroke of luck when he pulled his drive on the 10th into thick rough, but was allowed to take a free drop into the first cut due to a television tower being between him and the green.

Lowry's three-putt bogey on the 10th left Johnson two shots clear, but Lowry reduced the deficit with a tap-in birdie on the 12th.

American Scott Piercy was a shot further back after three birdies and 11 pars in his first 14 holes, with Sergio Garcia another stroke adrift after holing a 30-yard bunker shot on the 299-yard par-three eighth for birdie.

Johnson three-putted the 14th to drop back into - for the time being at least - a tie with Lowry, only for the Irishman to do exactly the same in the group behind.

Piercy also three-putted the 16th from long range to fall two behind Johnson, with Garcia's challenge seemingly over after three bogeys in a row from the 14th and Day's coming to an end with a double bogey on the 17th.

Another three-putt on the 16th dropped Lowry two shots off the lead and with Piercy unable to make birdie on the short 17th, Johnson had a two-shot lead over both men.

With Piercy dropping a shot on the 18th, Johnson had a vital three-shot cushion but made absolutely certain thanks to a stunning approach to the 18th and holing from five feet for birdie.

Johnson was greeted on the 18th green by wife Paulina and son Tatum and added: "It means the world. It's Father's Day. My birthday's in a couple of days. Couldn't have come at a better time."