Kenny Roberts Jr kept his head, and his balance, to win his third GP500 race of the season, while Olivier Jacque and Simone Sanna won their first apiece in GP250 and GP125 respectively.
The American made hay while the sun tried to shine at the Circuit de Catalunya, capitalising on a good start and the misfortune of his main rivals to re-establish his championship lead over Carlos Checa. The Spaniard was one of many to crash out on the slippery track, allowing Roberts to head Norick Abe
and Valentino Rossi
on the podium.
The race should have belonged to pole-sitter Alex Barros
but, once again, the Brazilian made a hash of the start and was left to battle through the pack. Despite the task ahead of him, Barros found his Emerson-backed Honda performing better in the conditions than almost anything else, and swiftly closed down and passed Roberts, who had once held a six second lead over the field.
Barros' lead was short-lived, however, and, almost exactly a lap after passing Roberts, his bike slowed dramatically as water drowned the electrics, and he was forced to return, slowly, to the pits.
Again, Roberts was left with an almost unassailable lead and, try as he might, Abe could not bridge the gap before time ran out. The Japanese rider nevertheless put in another mature performance on the d'Antin Yamaha to take second, and closes up on the luckless Checa in the overall standings.
The works Yamaha man crashed out as early as lap five, having just lost second on the road to the flying Barros. The pressure of trying to keep up with championship co-leader Roberts forced Checa to push that little bit too hard, and his bike rewarded the Spaniard by spitting him off into the gravel in front of Alex Criville's fan club. He was joined quickly by new third placed man - and fellow Iberian - Sete Gibernau, giving the fans somewhere to vent their anger at Criville's poor performance. Their ire was then raised even higher within a few laps, as the reigning champion joined his countrymen in the gravel, continuing a disappointing title defence for the Repsol rider.
The demise of the Spaniards ahead of them left Valentino Rossi
and Nobuatsu Aoki scrapping for the final podium place and, with the track steadfastly refusing to dry through the middle portion of the race, things always looked more likely to go the Japanese rider's way.
With ten laps to run, Aoki duly made the most of Rossi's uncertainty in the wet to move his Suzuki into third, and the Spanish looked set to have something to cheer - even if it was only a double podium for sponsors Telefonica and Movistar. A twitchy moment eight tours later reversed the places once and for all, however, and handed Rossi his third rostrum finish of the season.
Behind them, the man on the move was now Max Biaggi, determined to put his recent run of misfortune behind him and claim some real points. Having initially run as low as ninth, in the company of Criville and Jurgen van der Goorbergh's privateer Honda, the Italian finally came through to fifth, having passed Mugello nemesis Loris Capirossi
in the process.