Moseley matched Clarke's 65

But there was more bad news for out-of-form Lee Westwood.

He was forced to withdraw from the first round after five holes because of an arm injury.

But he is hoping a two-week rest will solve the problem.

"I've had this once before, so it shouldn't be too much of a problem," said the 29-year-old.

"I've had it for about four days now and as soon as I got a driver in my hand I didn't feel like I could hit it with any sort of confidence."

Clarke was paired with another of the five US Open-bound players in the field - defending champion Peter O'Malley - and Ian Poulter, runner-up to Justin Rose at the British Masters last Sunday.

The group had 18 birdies between them, but Poulter bogeyed two of the last four holes for a 68 and O'Malley did the same for a 69.

Poulter had earlier hit his stride with five birdies in his first 11 holes, while Australian O'Malley grabbed birdies at the 10th and 11th holes.

Clarke, seeking his first win since the European Open in Dublin last July, posted birdies at the 12th and 14th to draw level with Poulter.

But Clarke took the lead with another birdie on the 466-yard sixth while Poulter made the first of two successive bogeys.

That followed a hold-up ahead of them when the caddie of Welshman Stephen Dodd, Londoner Paul Ray, fell ill and needed attention.

Rose is one of the favourites after his victory last week

After waiting for medics to arrive Dodd continued with a friend carrying his bag.

"It was a bit of a shock to see something like that," said Dodd after double-bogeying the last for a 71.

"He was breathing heavy and said he didn't feel well walking down the sixth.

"He appeared to have a fit, but John Paramor [the European Tour's chief referee] told me going down the last that Paul was OK."

Australian Moseley, who equalled the course record at Wentworth two weeks ago with a closing 63, birdied two of the last three holes to join Clarke on seven-under-par.

Among the group on four under was Sam Walker, a 23-year-old from Birmingham whose brother Josh was on Manchester United's books.

Walker came through the qualifying school at the fourth attempt last November, but currently languishes in 157th place on the Order of Merit.

First-round leaderboard (GB and Irl unless stated):

65 Darren Clarke, Jarrod Moseley (Aus)
67 Gary Orr, Didier De Vooght (Bel), Graeme Storm
68 Peter Fowler (Aus), Mark Pilkington, Sam Walker, Ian Poulter, Jamie Donaldson, Dennis Edlund (Swe), Yeh Wei-tze (Tai)
69 Paul Casey, Shaun Webster, Peter O'Malley (Aus), Peter Baker, Robert-Jan Derksen (Ned)
70 Raphael Jacquelin (Fra), Nick Dougherty, Charlie Wi (Kor), Daren Lee, Sam Torrance, David J Russell, Michael Archer, Michele Reale (Ita), Russell Claydon, Joakim Haeggman (Swe), Santiago Luna (Spa)
71 Mark Mouland, Robert Coles, Robert Rock, Adam Mednick (Swe), Barry Lane, David Gilford, Paul Broadhurst, Stephen Dodd, Darren Ficharedt (Rsa), Philip Walton, Simon Khan, Des Smyth
72 David Park, Mikael Lundberg (Swe), Federico Bisazza (Ita), Benn Barham, Malcolm Mackenzie, Andrew Oldcorn, Brian Davis, Anthony Wall, Marcel Siem (Ger), Klas Eriksson (Swe), Ian Hutchings (Rsa), Matthew Cort, Marc Pendaries (Fra), Andrew Marshall

Withdrawn: Lee Westwood, Tony Johnstone (Zim)