Free practice 4: Barrichello fights back

For most of the 45-minute session, Schumacher sat unchallenged at the head of the times, gradually improving on his previous best. With 15 minutes remaining both Juan Pablo Montoya and Ralf Schumacher threatened to match the world champion's pace, but he duly took his Ferrari around in the first sub-2001 pole lap.

However, when Barrichello blitzed the final sector of an already impressive lap, Schuey found himself two tenths down with just a few minutes to go. There was time for one last effort though, and through the first two timing points the championship leader held an advantage. But he pushed too hard through the important final corner, Woodcote, and ran wide and onto the grass, which cost him precious time.

Behind the leading two teams there was a small gap back to the McLarens, with David Coulthard four tenths up on Kimi Raikkonen. The Finn was just 0.001s quicker than former Sauber team-mate Nick Heidfeld, who had been as high as third during the session.

Jenson Button made a late improvement to claim eighth ahead of the impressive Heinz-Harald Frentzen and Jacques Villeneuve. Frentzen's session got off to an ominous start when his car expired on the pitlane exit and the German had to push it back to the Arrows pits where the problem was quickly fixed. Later on he had a brief off at Chapel, but considering the weekend the team has endured it was a good performance.

The two drivers who missed out in the previous session, Eddie Irvine and Giancarlo Fisichella, both managed to get some valuable track time. Irvine was fractions quicker than team-mate Pedro de la Rosa in 13th, while Fisichella was likewise just a bit faster than Takuma Sato as the Jordans finished back in a disappointing 16th and 17th.

Olivier Panis also showed signs of frustration as his BAR coasted to a halt, leaving the Frenchman back in 20th ahead of just the Minardi's. Alex Yoong had a quick spin at Vale but continued, but Mark Webber was less fortunate when his PS02 stopped on track with just a few minutes remaining.