Padraig Harrington back in contention

On a day of squally weather on the Costa del Sol, the Irishman's two-under-par 69 gave him a level-par total of 142, four behind tournament leader Henrik Stenson of Sweden (68).

While Paul Casey, recovering from a stomach upset that led to an opening 76, is still in position to clinch the order of merit in the final event of the season, Harrington is coming up fast on the rails.

Harrington needs to finish at least third at Valderrama, with Casey out of the top-35. The Irishman was joint ninth at the halfway stage and the Briton joint 35th.

"There is a little bit more expectation now," Harrington told reporters. "My dual agenda is looked after by winning the tournament.

"I don't really need to worry about the order of merit. I just need to keep myself in contention and then, with nine holes to go, see what happens," added the 2001 Volvo Masters champion.

Harrington, 147,041 pounds ($277,900) behind Casey, is not the only player with a chance of being crowned Europe's number one.

Briton David Howell, third on the order of merit, birdied the last two holes for a 73 to lie five strokes off the pace alongside Swede Robert Karlsson (74), who is fourth in the rankings.

Howell and Karlsson are likely to have to finish no worse than second to top the money list.

Casey said he would have been unable to play the second round had he been as ill as he was on Thursday night.

The Englishman's improvement in health and scoring, a 72 for a total of 148, encouraged him to look optimistically at the weekend.

"There's not a lot I can do apart from try to play well at the weekend and crunch some numbers to make it difficult for the others," said Casey.

He is by no means the only one to suffer from a stomach bug. Players David Lynn, Simon Wakefield and Soren Hansen, several caddies and players's wives and six courtesy car drivers have gone down with gastric problems.

Lynn spent the night in hospital on a drip and only narrowly made his tee-off time. But a 71 moved him within two strokes of the lead alongside fellow Britons Philip Archer and Luke Donald and Richard Green of Australia.

The pacesetting Stenson birdied five holes in succession from the 13th, chipping in twice, to go one shot clear of 1997 champion Lee Westwood (70).