Mark Webber became the first Australian to win in the International F3000 series as he overcame home favourite Darren Manning and some unpredictable weather to take Silverstone's International Trophy.

The European Arrows Junior driver started second on the grid behind Manning's Arden Lola, and was forced to watch as the Yorkshireman disappeared in a ball of spray early on. The race start had been delayed by 15 minutes by a heavy rainstorm, and caused the first five laps to be run behind the pace car. When the Mercedes departed, however, Manning had the best view and made the most of it to open out an early advantage, repeating the sort of form which took him to the head of the field in qualifying.

Behind Webber, Justin Wilson held station in third, ahead of Enrique Bernoldi and Bruno Junqueira. Already missing from the qualifying line-up, however, were the Astromega duo of Fernando Alonso and Fabrice Walfisch. The Spaniard didn't even take to the grid after the team's appeal against his disqualification failed, and his French team-mate spun off while lapping behind the pace car.

Championship favourite Stephane Sarrazin compounded his practice misery by spinning away any chance of race success at Becketts, while championship leader Nicolas Minassian had to be content with an afternoon in the midfield. Fourth placed at Imola in round one, Jaime Melo Jr saw his chances of progressing through the field at Silverstone ruined by a tangle with Ananda Mikola while disputing 20th place, which dropped the Brazilian to the tail of the field.

Back at the front, Manning was forced to watch as Webber closed remorselessly in his mirrors. The Arden car was struggling as the circuit dried out, and Webber was right with it as the race approached half distance. Then, on lap 15, the Australian was alongside his rival heading into the Vale, forcing his way through at Club and leaving Manning half spinning as a result of contact.

From then on, Webber pulled away, opening out as much as a four-second advantage as Manning found Wilson looming behind him. The second Orange-backed car of the Australian's team-mate Christjan Albers was also on the move, homing in on Soheil Ayari and making several moves to pass before eventually finding a way through. Once past the stubborn Frenchman, however, the Dutchman pulled away at a rapid rate, but ended his afternoon with a trip into the barriers at Chapel when closing on Junqueira.

The conditions left the field strung out for the most part, but the midfield battle between Franck Montagny, David Saelens and Kristian Kolby kept the crowd entertained for long periods. The Dane then succumbed to the attentions of both Jeffrey van Hooydonk and Sebastien Bourdais, and had to settle for twelfth at the flag.

Webber's path to victory looked assured until the conditions became almost dry enough for slicks. The Australian later admitted to a little bit of complacency with his advantage over Manning, but it was the Yorkshireman's gain in pace which brought the gap down to around a second with two laps to run. Successive trips deep into Brooklands cost Manning the chance to challenge before the flag fell, however.

Wilson completed the podium after a relatively uneventful afternoon, his challenge to Manning falling away as the track dried. Bernoldi took fourth, comfortably ahead of compatriot Junqueira, with Ayari, now free of attention from behind, held on to take sixth without any of his usual grassy excursions.

Others were not so innocent, however, with Sarrazin further blotting his copybook at Bridge, Ricardo Mauricio spinning at Becketts and later colliding with the storming Bas Leinders at Club, and both Tomas Enge and Mario Haberfeld finding themselves on the grass more than once.

Victory a Silverstone leaves Webber at the top of the championship, adding ten points to his four from another podium visit at Imola. Manning slots into fourth overall, behind Imola winner Minassian and podium finisher Junqueira.