Ireland's Shane Lowry had a huge battle on his hands to claim his first major title as the US Open headed for a thrilling climax at Oakmont on Sunday.

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.

However, 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.

Spain's Sergio Garcia was two shots 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.

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."

Willett, meanwhile, admitted frustration got the better of him after smashing the putter he used to win the Masters during Saturday's third round.

A closing 71 left the 28-year-old on nine over par alongside Argentina's Angel Cabrera, who was five over par in winning the US Open at Oakmont in 2007.

"Unfortunately it's now in two pieces," said Willett, whose patience ran out in the closing stages of Saturday's third round of 73. "We'll have to get it refurbed and then I won't be using it again.

"The putter has been bad all week, just a bad week really on the greens. They're tricky to read, tricky to keep the pace and line the same.

"Luckily enough I did [have a spare putter] this week. I've been doing a little bit of work at home and it's not quite been spot on. Paul Hurrion [putting coach] was out this week trying to get a bit of work done.

"It was a week that could have been pretty good. I think we had 33, 35, and 33 putts the first three days. It's not really going to put you anywhere near contention with that amount of putts on this golf course."