US Open: Dustin Johnson reels in overnight leader Shane Lowry on final round at Oakmont

American sat four shots behind Irishman after round three but made up ground

Dustin Johnson moved to the top of the leaderboard halfway through Sunday's final round (Getty)

Dustin Johnson reined in Shane Lowry as the final round of the US Open got underway in Oakmont.

Both players were seeking a first major title and Lowry took a four-shot lead into the final round, armed with the knowledge that the late Payne Stewart was the last man to enjoy such a lead and not secure victory.

Stewart was four ahead at the Olympic Club in 1998 before shooting a closing 74 to lose out by a shot to Lee Janzen, but Tiger Woods (twice), Rory McIlroy and Martin Kaymer had all since converted commanding leads into victories.

Lowry could also reflect on the good omen that his world ranking of 41 was exactly the same as that of Angel Cabrera when the Argentinian won his first major title at Oakmont in 2007.

But the 29-year-old's lead was quickly cut in half when Dustin Johnson drove the green on the short second to set up a birdie and Lowry bogeyed the same hole after laying up off the tee and spinning his approach back off the green.

And when Lowry mishit his recovery from a fairway bunker on the fifth and did well to salvage a bogey, the gap was down to a single stroke.

Johnson tied with Lowry by the ninth hole before the Irishman dropped another shot to allow Johnson to move to the top of the leaderboard. He sat two shots clear after 10 holes.

Spain's Sergio Garcia sat further back after kickstarting his bid for a first major title in spectacular fashion, the Ryder Cup star holing a 30-yard bunker shot on the 299-yard par-three eighth after a bogey on the previous hole.

American Scott Piercy was alongside Garcia on two under after birdies at the first two holes, with former champion Jim Furyk - runner-up the last time Oakmont staged the US Open in 2007 - one under with three to play.

A victory for Lowry would mean 10 of the last 36 majors have been won by Irish golfers after the successes of Padraig Harrington, Rory McIlroy, Darren Clarke and Graeme McDowell, although the 29-year-old from Offaly would be the first from the Republic of Ireland to win the US Open.

It would also represent the first time since the inception of the Masters in 1934 that European players had won the first two majors of the year after Danny Willett's victory in the Masters in April.

Shane Lowry was unable to maintain his form into the early part of the final round of the US Open (Getty)

And more importantly it would take Lowry into the automatic qualifying places for the Ryder Cup, ending any concerns about opting to defend his WGC-Bridgestone Invitational in a fortnight's time rather than contesting the French Open.

Double Ryder Cup points are on offer in Paris after the European Tour responded to the clash of dates by offering incentives to attract some of its star players to Le Golf National.

As Lowry had made his way to the first tee, American Brooks Koepka had given the chasing pack plenty of hope and threatened to create history with a remarkable round.

Koepka bogeyed the first and third, but then birdied the next four holes and picked up another shot on the ninth to reach the turn in 32, before holing his approach to the 10th from 108 yards for an eagle.

And when the highly-rated 26-year-old then chipped in for a birdie on the 11th, he had completed his last eight holes in eight under and needed to play the remaining seven in two under to card the first 62 in major history.

However, Koepka's round collapsed with four bogeys in a row from the 14th and the world number 16 eventually had to settle for a 68 to finish four over par.

Johnny Miller famously won the US Open at Oakmont in 1973 with the first 63 in any major and Koepka said: “I knew that. I was hoping for something even lower.

”I was hoping for 60, 61. I thought that was pretty obtainable. The four iron we hit in the bunker on the 14th was just an awful tee shot. You put that one in the fairway, you're making a good run.“