Kubica shines after Montreal accident

The Pole drove a lonely race to take fourth place and, with teammate Nick Heidfeld finishing behind him, he was overjoyed with the way the team strengthened their grip on third place in the constructors' championship.

"This was a good race for the team with us finishing fourth and fifth, and it has been a very good weekend for me," said Kubica. "It was a very quiet race.

"I made quite a good start but we were on the dirty side with Lewis Hamilton, so had no chance to overtake. After that I was close to him just once when he was coming out of the pits and we had a short fight, but he had new tyres, braked later into the hairpin and overtook me again.

"The last 20 laps were about bringing the car home for a good result for the team, as Lewis was a long way in front and Nick behind.

"The car was very good, physically I am a hundred per cent and mentally too, and I could do another race now."

Heidfeld enjoyed several battles with world champion Fernando Alonso during the race but was not impressed by a defensive move that Giancarlo Fisichella pulled on the first lap.

"At the start both Renaults went to the middle of the track," said the German. "I tried to overtake Giancarlo Fisichella on the right hand side, but he moved over, which was not correct.

"The fights with Fernando Alonso were a lot of fun and also useful for my result. At times I had to defend hard, but I think from both sides it was fair play. It was not easy to keep him behind me, especially as in the middle stint he was very fast with obviously a low fuel load.

"Ferrari was very strong here as we already saw at the last test. You should never discount Renault as they are the reigning champions."