With fellow championship leader Sete Gibernau falling early in Sunday's Rio Grand Prix, Valentino Rossi was presented with the perfect chance to put points between himself and the Spaniard... but then made a rare mistake of his own - crashing out of a GP for the first time since 2001.

The 24-lap Rio race began brightly for Rossi as he jumped from eighth to fifth at the first turn and, after Gibernau crashed out on lap two, the Italian would go on take fourth from Kenny Roberts, before rising to third on lap eight after passing local hero Alex Barros.

The five-times world champion then took on the task of reducing the 1.6secs gap to race leaders Max Biaggi and Nicky Hayden - but was also facing considerable pressure from eventual race winner Makoto Tamada.

A mistake on the twelfth lap allowed Tamada to pass, but things would get much worse for the #46 one lap later when he lost the front of his M1 at the last left hand corner on the Jacarepagua circuit and slid into his first DNF since Brno 2002. On that occasion Rossi was forced to stop after a tyre failure - he last fell from a GP at Mugello in 2001!

"What a shame," sighed Rossi. "I lost the front and that was it. I haven't fallen in a race since Mugello 2001. We've been having problems all through the weekend, but we were having a strong race and I felt I was catching the leaders.

"Even though I was up with the front group it was very difficult on the left hand corners. If I had managed to finish in fourth place it would have earned us some good points," he admitted.

"It's a missed opportunity because we could have gained some points on Sete," added factory Yamaha team director Davide Brivio. "Valentino is a fighter and that is probably what has helped him get so many victories in the past but today it didn't work out that way. The main thing is that we restart in Sachsenring still leading the championship, so that is the positive side of the story."

Despite his DNF, Rossi still leads the championship, sharing a 126-point total with Gibernau, but ahead because of his better win ratio. Third placed Max Biaggi, second on Sunday, has now moved to within 13-points of the top two.