Graeme McDowell’s US Open challenge appears to have fallen by the wayside as the final round nears completion at Bethpage in New York. Three dropped shots have seen McDowell fall to three over par, and although the leaders are also moving backwards he is now seven shots off the pace.

Rory McIlroy carded a final round of 68 for a two over total and will finish inside the top 15 for his best result in a major tournament.

Phil Mickelson, England’s Ross Fisher and even Tiger Woods were in contention for the title as the tournament was blown wide open by a final-round collapse from third-round leader Ricky Barnes.

American Barnes, without a victory in six years as a professional, was doing a good job of extending that streak, his final-round imploding as play resumed at the par-70 Bethpage Black.

England’s Fisher began the fifth day of this rain-hit championship five strokes behind overnight co-leader Barnes, who was at seven under par and in thick rough at the second hole when play was suspended last night due to fading light.

Tied for third, Fisher had bogeyed his opening hole in the evening gloom on Long Island to drop to two under but Barnes followed suit to fall into a joint lead with Lucas Glover at seven under.

When play resumed today morning, the first time since 1983 that a US Open had extended into an extra day to complete 72 holes, Barnes managed to find the second green out of the rough to make par.

Fisher, runner-up behind Paul Casey at last month’s BMW PGA Championship at Wentworth, was ready to go also and he rolled in a three-foot birdie putt at the par-five fourth to get back to three under, four shots behind Barnes, with Glover bogeying the third to slip to six under.

Hunter Mahan had been at three under with a birdie at the fourth ahead of the Englishman but the US Ryder Cup player then bogeyed the par-four fifth and was tied for fourth at two under after five with playing partner Mickelson.

World number two Mickelson, though, bogeyed sixth and fell to one under while former Open champion David Duval, in the wilderness since his 2001 victory at Lytham, was quickly in trouble with a triple bogey at the par-three third, after his tee shot plugged underneath the lip of a greenside bunker.

Duval showed resilience by sinking a birdie at the next hole, the par-five fourth to get back to level par.

Everything changed, though, when Barnes began to slide back to the field. Both he and Glover bogeyed the fifth hole but Barnes would bogey three more in succession to fall to three under after eight as Glover assumed the lead at five over.

Then Glover bogeyed the ninth and was leading at four under after 10 with the tournament wide open.

Fisher had bogeyed the fifth and the seventh to drop to one under but a super iron shot to inside two feet led to a birdie at the ninth and after nine holes he was within two shots of the lead at two under.

Mickelson had also been in trouble, bogeying the sixth and the eighth to fall to level par, but he birdied the ninth as Barnes fell apart and then the four-time runner-up got to two under with a birdie at the 12th.

Fellow American Mahan also got to two under after 12 for a three-way tie for third, two shots behind Glover.

Defending champion Woods got to one under alongside Mike Weir of Canada thanks to consecutive birdies at the 13th and 14th, although his charge was checked by a bogey at the difficult par-four 15th.

At level par he was running out of holes but still in contention with the stuttering leaders heading into the back nine.

The Players champion Henrik Stenson posted a 68 to get to one over alongside fellow Swede Peter Hanson, who had played 14 holes.