United States duo Matt Kuchar and Gary Woodland win World Cup

Woodland and Kuchar won the World Cup for the US for the first time since 2000

United States duo Matt Kuchar and Gary Woodland hit six birdies in a closing 67 to win the World Cup by two shots.

The Americans eroded the overnight two-stroke lead held by Ireland's Rory McIlroy and Graeme McDowell in China, with birdies on the first two holes.

Four more birdies lifted them to 24 under as Ireland faded with four bogeys in a level-par 72 to stay 21 under.

England's Ian Poulter and Justin Rose carded a nine-under-par 63 to finish second alongside Germany on 22 under.

"We were a little subdued [after the third round] and neither of us were much company," admitted Poulter.

"We stayed in our own rooms, and kind of rightly so as four under par in fourball was very disappointing.

"But to go and shoot nine under par in foursomes is crazy."

Poulter and Rose sank four birdies on the front nine and finished with two birdies and an eagle in their last four holes as they recorded the lowest score of the final round at the Mission Hills course on the southern Chinese island of Hainan.

But although they caught and passed McIlroy and McDowell, who had held an eight-shot advantage over the Englishmen going into the final round, they were unable to match the Americans.

Kuchar and Woodland played solid, rather than spectacular, golf in the alternate shot foursomes format as they finished with a five-under-par 67 to record the United States's first victory in the tournament since Tiger Woods and David Duval teamed up in 2000.

"You think of all the sporting events, and you think of all the teams that become world champions, and in golf there are not that many opportunities to be world champions," said Kuchar.

"So to represent the United States of America and become world champions just feels great."

Their only blip was a bogey on the par-three 11th, but that dropped shot was wiped out on the 12th with a sixth birdie of the round following on the 13th.

In contrast, McIlroy and McDowell, who led by three on the back nine two years but were beaten to the title by Italian brothers Francesco and Edoardo Molinari, again struggled on the final day.

They mixed two bogies with two birdies on the front nine to fall two behind the Americans.

A birdie on the 10th brought them within one shot of the lead, but a bogey on 12 checked their progress and another shot went on the par-three 15th after McDowell's tee shot plugged under the lip of a greenside bunker.

McIlroy could only blast the ball a few feet out of the sand but when his playing partner missed the 25-foot par putt, their challenge was effectively ended.

They finished joint fourth with Australia, Netherlands and Scottish pair Martin Laird and Stephen Gallacher who closed with eight birdies in a six-under-par 66.

German duo Martin Kaymer and Alex Cejka did not drop a shot over the last two rounds and played the final 18 holes in a three-under 69, sinking a lengthy par putt at the last to ensure they finished joint second.

The World Cup used to be held annually but was switched to biennial after 2009 to accommodate golf's inclusion in the 2016 Olympic Games.