The unheralded duo of Boo Weekley and Heath Slocum shot the USA to the top of the Mission Hills World Cup leaderboard at the end of the first round's play in China.

Weekley and Slocum may not be household names in comparison to previous representatives of the United States such as Tiger Woods and Phil Mickelson, but they produced a strong performance on Thanksgiving Day to move into a one-stroke lead with an 11-under 61 in fourballs.

Defending champions Germany were in second place on 10 under, after Alex Cejka and Martin Kaymer combined to card an overall 62 - while England, Scotland and Wales joined three other teams a shot further back tied for third.

Ireland's Michael Hoey and Gareth Maybin are six under after a 66.

Weekley got the United States off to a good start with a birdie on the first, before Slocum putted for an eagle on the par-five third.

Weekley picked up two more shots on the seventh and ninth to ensure they reached the turn a five under.

But it was coming home when they really picked up shots, Weekley carding a birdie on the 11th before making an eagle on the par-four 12th and Slocum following up with a birdie on the 13th.

Weekley then sent the USA top with two successive birdies from the 16th.

England duo Justin Rose and Ian Poulter made a solid start - with the latter particularly impressive, carding two eagles as the two-time winners finished at nine under.

After slow start on the first eight holes, in which Poulter carded two birdies while Rose managed just one, the Hitchin-born golfer shot an eagle on the long par-five ninth.

Poulter added his second eagle just two holes later, before making another birdie on the 15th at the Olazabal course's signature hole.

Rose then putted for a birdie on the last to secure a place among the chasing pack before tomorrow's foursomes.

"I think we played steadily," said Rose. "We didn't make too many birdies or too many putts, but we made key putts.

"We didn't make any mistakes and didn't make any bogeys - which is obviously what kills you out there."

Scotland's Colin Montgomerie and Marc Warren combined to card an impressive first-round score.

Last year the duo shot a 67 on the opening day in Barbados, before losing out in the final round in a play-off against Germany.

This time, a good run on the front nine in which Warren carded two birdies to Montgomerie's three propelled them up the leaderboard before a combined total of four coming home cemented their place among the clubhouse leaders.

Bradley Dredge and Stephen Dodd also made the ideal start as they look to secure a second World Cup victory in two years - carding an eagle and eight birdies while dropping one shot.

Retief Goosen and Trevor Immelman, who have both tasted success in previous incarnations of the tournament - though with different playing partners - were also in the clubhouse at nine under.

Joining them were Finland, who had set the nine-under benchmark for the rest - having teed off first in the morning - and Thailand.