FIRST ROUND LEADERBOARD GB & Ire unless stated otherwise -6 D Clarke, P Hanson (Swe) -5 P Casey, J Sandelin (Swe), M Campbell (NZ) Selected others: -3 I Woosnam -2 P Broadhurst, MA Jiminez (Sp), S Lyle, L Westwood level Pa Lawrie, C Montgomerie, A Cabrera (Arg)

The Northern Irishman nearly pulled out on the eve of the event as his wife Heather continues to battle cancer.

But Clarke chose to play and shot a superb 66 to match Hanson at six under par on top of the leaderboard.

US Open champion Michael Campbell and England's Paul Casey are among a group of four players on five under.

Clarke's schedule has been in disarray for some time and he played badly in Wednesday's pro-am at The Belfry.

"The last thing I expected was to be talking about a 66 after the way I played in the pro-am," admitted Clarke.

"I talked myself into staying because it would not have been the right thing to do to pull out, not very professional.

The course is a little bit of a sanctuary for me at the moment Darren Clarke

"After the pro-am it was a case of breaking a few clubs or going back to the range and I chose the latter. I played not great but not bad today.

"My mind is obviously elsewhere and I'm preoccupied with other things and that sometimes seems to benefit my golf.

"I'm trying not to get too upset with how I'm playing and I'm shooting some good scores. It would be nice to get in a run, play three or four tournaments in a row and see how I get on.

"I can't sit at home, I've got to get out and do something. The course is a little bit of a sanctuary for me at the moment."

Casey, winner of this year's China Open and with four other top-10 finishes to his credit this season, continues to show he is over last year's slump.

Lying 57th in the world rankings, he is determined to return to the world's top 50 in time to qualify for the US Open next month, after missing this year's Masters.