BRNO, August 17, 2008 (AFP) - World champion Casey Stoner of Australia crashed out of the MotoGP race at the Czech Grand Prix on Sunday.

The Ducati star, who had battled with flu-like symptoms here on Saturday to claim his sixth successive pole position, was forced to withdraw after just six laps on the Brno circuit.

Stoner fell on a right bend and slid across the track and into the gravel as he was leading the race, one second ahead of Italian Yamaha rider Valentino Rossi, who is leading the MotoGP standings.

The Australian attempted to get back into the race but was forced out because of damage to his motorcycle.