Italian Valentino Rossi started his quest for a fifth successive world title in the most dramatic style on Sunday, winning the MotoGP Spanish Grand Prix after his main championship rival Sete Gibernau went off the track at the last corner.

Local favourite Gibernau had led on his Honda for all but two of the 27 laps in the race before Yamaha rider Rossi took the lead.

The pair, first and second in the title race last year, swapped back and forth over the last two circuits of the track and made contact just before the final corner with Gibernau ending up in the gravel trap.

Gibernau's Italian team mate Marco Melandri finished third, taking advantage of American Honda rider Nicky Hayden's crash on lap 20 to match his best result in a MotoGP race.

Earlier, the crowd celebrated a victory for Honda and Spain when 250cc world champion Dani Pedrosa took his first career win at his home Grand Prix. Italian teenager Marco Simoncelli recovered from a poor start to win the 125cc race on his Aprilia for the second year in a row.