European challengers looking at the leaderboard here at Valderrama, must be wondering if jet-lag could come to their rescue. Otherwise they may be facing a weekend of US supremacy in the £3 million WGC American Express Championship, in which Tim Herron and Chris Perry are joint leaders on 137 - five under par.

Among the supporting cast, Justin Leonard hovers a stroke back with overnight leader Vijay Singh. And there was a best-of-the-day 65 from Stewart Cink. But a far more menacing figure is that of world number one, Tiger Woods, who birdied two of his last three holes to get within comfortable, striking distance at two under par with 36 holes to play.

In terms of age and world ranking, Lee Westwood looks to be the strongest European on two under, after a sparkling 67. Yet the fact remains that the frontrunner from this side of the Atlantic happens to be 46-year-old Mark James. And his post-round comments were not especially inspiring.

What would he do with the dream prize of £609,422? "I'd buy a stereo, because my friends say the one I have is not good enough," he replied. "I was dreaming more of a four-figure cheque." Then he added: "I hope I haven't a three-foot putt to win. It might finish in a bunker."

Against that background, Darren Clarke had reason to feel rather pleased with himself after a 67 which was a full 12 strokes better than Thursday's effort. Not surprisingly, he improved his placing dramatically, from tied 61st overnight, down to a share of 40th.

But Padraig Harrington was left somewhat anxious about his precious world ranking of 49th, after adding a 74 to an opening 76. Crucially, it contained three successive bogeys at the 13th (wayward drive), 14th (another wayward tee-shot) and the 15th (three putts), leaving him little scope for remedial action.

"I seem to have run out of steam," he said afterwards, thoroughly deflated. "This course is tough enough without the silly mistakes that I've been making." He added: "I'm physically strong but mentally tired. But things could be different next week when I play in the Johnnie Walker Classic (in Taiwan)."

Harrington's concern about the world rankings is that he must remain in the top-50 at the end of the year so as to be sure of playing in next April's US Masters.

After Thursday's collapse, Clarke set his sights on a level-par aggregate for the tournament. And he made rather a clever move in that direction by opting to return to the golf course for short-game practice on Thursday evening, rather than to his hotel in nearby San Roque.

The upshot was that he met British Open champion Paul Lawrie on the putting green and received an invaluable tip. Then, after an almost mandatory change of putter, he seemed to hole everything, using the blade only 28 times in the first pairing on the course yesterday with Alexander Cejka.

Further up the leaderboard, a Westwood victory on Sunday would mean Colin Montgomerie having to finish third, at worst, to lead the Order of Merit for a seventh successive year. And if Sergio Garcia were to win, the Scot would have to finish second. But as Woods observed: "Even if Monty is pipped for the Order of Merit, he still must be Europe's player of the year."

For his part, Montgomerie made no bones about the fact that he's feeling the pinch. "I'm playing against myself and the rest of the field: the stress levels are high, to say the least," he remarked after a disappointing 72 which left him level-par overall.

Woods looked to be in a commanding position when a birdie at the short 12th left him two under par for the tournament. But he was then rocked by a double-bogey at the treacherous, 225-yard 15th, where an intended fade with a three iron turned into a very costly hook.

Having landed on a cart-path, he got relief and proceeded to hit his recovery off a tree into a gully. From there, a delicate pitch just cleared the lip of a bunker and he then had to play an even more precise flop-shot to get the ball within 12 inches of the cup. It all added up to an ugly, double-bogey five.

Still, the American retained his composure, sinking a 10-footer for a birdie at the next and then getting up and down from a back bunker for a four at the long 17th. The two strokes had been retrieved. "I hit the ball better today and I putted better," he said, confidently.