Marco Simoncelli's nightmare run of race-day incidents continued at Assen on Saturday, when the Dutch TT pole sitter crashed after just a few turns, bringing down world champion Jorge Lorenzo.

Having lost out to Lorenzo and factory Yamaha team-mate Ben Spies through the first few turns, Simoncelli attempted to re-pass Lorenzo for second at the following hairpin.

The Italian made the initial move cleanly, but - as in Estoril - was caught out by his cold-rear tyre on the first left-hand turn of the track and highsided as he applied the power.

Simoncelli's bucking Honda then took down Lorenzo (see below for more pictures).

A livid Lorenzo rejoined to finish sixth, while Simoncelli - who struggled to restart his RC212V - climbed to ninth at the chequered flag.

Simoncelli - a top-two starter for the last five rounds - has now crashed in four of the seven races this year, and received a ride-through for a collision with Dani Pedrosa at another (Le Mans).

The former 250cc world champion had already been heavily criticised by some riders (including Lorenzo) for his aggressive style - but is popular with many fans for the same reason.

Unsurprisingly, Lorenzo was angry with the Assen incident, which means he has dropped from 18 to 28 points behind world championship leader Casey Stoner, who finished second to Spies on Saturday.

"Of course Simoncelli doesn't want to throw me off the track, that wasn't his intention but I think he is not very conscious about the risks in this class with these tyres," said Lorenzo.

"I thought he learnt from the past and the polemic he created with Dani [Pedrosa] but it's clear he hasn't learnt.

"The good thing is that we finished in sixth and took some points. I was fast with a good pace. The championship is now more difficult so we have to go all out to win races and go fast."

"It was a racing accident but pretty stupid," summed up Yamaha team manager Wilco Zeelenberg.

Simoncelli, still without a MotoGP podium, held his hands up for the error.

"In this race you can't put it all down to bad luck, but the truth is that I was very na?ve," he said. "It was the first left hander, the asphalt was cold and, although I don't think that I went in too hard to get past Lorenzo, I felt that I couldn't hold back because I was third and close to the front two. There was time though, and I could have waited.

"I am unhappy to have caught Lorenzo up in my crash and can only apologise to him. The only consolation, small as it is, is that I was able to pick the bike up and finish the race and put down some good times - despite having parts and pegs missing from the bike and the back of my helmet digging in.

"It is another bad experience for me and I am going to try and bear it in mind, without losing focus and motivation."

"The first left turn is always dangerous and the same thing happened here as in Estoril," added team manager Fausto Gresini. "It is a shame, because we were looking really good and capable of a great result. The move should have been held back for another couple of corners perhaps, and now our date with the podium has to wait once again.

"We are not angry, but the first person to be annoyed is Marco and we are all going to stick together. We want him to get out of this situation, because his motivation is as high as ever."

Simoncelli and Gresini's home race, the Italian Grand Prix at Mugello, takes place next weekend.