Rosberg aims to defend points position

Rosberg is seventh in the drivers' standings, four points ahead of Jarno Trulli - who has qualified sixth - while Williams holds sixth in the constructors', 2.5 points clear of BMW Sauber, which occupies row four.

But despite being behind his and the team's main rivals on the grid, Rosberg is sure he can do enough in the race to avoid losing ground in the standings.

"I think ninth was around the best we could get out of today, we are definitely struggling on the open sections of this circuit, but points are definitely possible here and very important for us this weekend," he said.

"From the fifth row and with a good strategy tomorrow, we can stay ahead of BMW in the constructors and I can hold seventh position ahead of Trulli in the drivers' championship. It's a good track, not easy and very hot but this is also the last race for me with Williams and I want to do the best for this great team."

The team's chief operations engineer Rod Nelson agreed that qualifying behind the BMWs was not ideal, but remained optimistic for the race.

"We hoped that Nico had another couple of tenths in him to get among the BMWs just in front, but he starts from the clean side of the grid and he should have a competitive race," Nelson said.

Kazuki Nakajima was only 14th in the second Williams after making a mistake on his last Q2 lap - although he was not sure if it really made too much difference to his position.

"I'm a bit disappointed because I didn't manage to put everything together in Q2, but there was still a reasonable gap to the first ten, so maybe I wouldn't have made it into the final qualifying session anyway," said Nakajima.

"The track demands that you are precise all the time and one mistake here is costly, which makes it pretty difficult.

"I don't think it will be easy to overtake tomorrow, but because of the nature of sectors one and two, we could have a pretty crazy first lap tomorrow, so I still believe anything is possible."