Valentino Rossi crashed and took out world championship leader Casey Stoner when an attempted overtake went wrong during Sunday's wet Spanish MotoGP at Jerez.
Rossi attempted to take second place from Stoner at turn one on lap 8 of 28, but lost the front and collected the Repsol Honda rider.
Bikes and riders were tangled together as they slid into the gravel, with Stoner's Honda lying on top of Rossi and his Ducati.
Rossi, aided by the marshals, rejoined at the back of the field while Stoner, winner from pole in round one in Qatar and also on pole in Spain, retired.
After finishing the race in fifth, Rossi went straight to the Repsol Honda pits to apologise.
Stoner, although smiling and accepting Rossi's handshake, said “Your ambition outweighs your talent” during the brief exchange, in which he also asked about Rossi's shoulder.