Juan Pablo Montoya was left to rue the shunt which led to him gifting second to Fernando Alonso at the Turkish GP.
Nursing a worn tyre late on, he spun when hit from behind by the Jordan of Tiago Monteiro but recovered - only to run off and finish in third place.
Montoya said: "I was just cruising past Monteiro and he hit me.
"I then went into turn eight and had lost downforce. It's disappointing. We were looking good for the constructors' championship if we'd had the one-two."
McLaren boss Ron Dennis did not completely absolve Montoya of blame and said: "I am upset at Juan Pablo to a certain degree.
"But at the end of the day, his car shouldn't have been damaged by a backmarker, especially one that is two laps down.
"It obviously spoiled a perfect day and gave away two points to Renault."
Alonso admitted he was lucky to steal second place and maintain a healthy 24-point lead in the drivers standings over McLaren's Kimi Raikkonen.
The Spaniard said: "I was surprised to see Montoya and Monteiro had collided and spun. Then Montoya had damaged his car and went off.
"Until then I thought it would not be possible to overtake him.
"So it was a nice surprise at the end to take second, but it was also a little disappointing because we were not fighting with the McLarens."
McLaren's Kimi Raikkonen kept his counsel on Montoya's late problems but admitted his fifth win of the season was "pretty easy" after an early skirmish.
The Finn was beaten by Giancarlo Fisichella of Renault from pole to the first bend but swept past him a few moments later.
"I didn't get the best start, I got a bit of wheel spin," he said. "But I was confident that we would have the speed.
"We had been quick all weekend and we had a big advantage on speed. The circuit was not bad physically, and I was able to just take it pretty easy."
Raikkonen added: "It would have been nice to have a 1-2, but what can you do? Sometimes it goes like this.
"It also would have helped me and the team. Two points are two points and they can make a big difference at the end of the season.
There's no way to gain any more than two points if Alonso keeps finishing second."