The race was won by Ferrari's Felipe Massa after team-mate Kimi Raikkonen suffered an exhaust problem while leading. However, such was Ferrari's dominance that the Finn still managed to finish second, with Toyota's Jarno Trulli third.
Nico's race was compromised by a 10-place grid penalty for his involvement in the pit-lane confusion at the previous Grand Prix in Canada, when he hit the back of a stationary car with the pit exit red light still on.
It affected his strategic approach to Magny Cours and meant that he started from the back of the grid. Even so, Williams did not enjoy one of its more competitive showings of the season.
"In Canada I was fighting the Ferraris and the BMWs and here I was at the back of the pack," said Nico. "It's incredible and not a very nice feeling. I thought I would be able to fight a bit more. I was giving it my all, as usual, but the car simply didn't have the speed and it was very difficult. I am now looking to score some points in the next race at Silverstone - at least I won't have a grid penalty there!"
The team elected to fuel Nico heavy and adopt a one-stop strategy, pitting after 40 of the 70 laps. Meanwhile, Kazuki ran a five lap shorter first stint and stopped at half distance and then again with 12 laps remaining. He crossed the line less than a second clear of his team-mate.
"It was a difficult race all round for us," said Kazuki. "We decided to opt for the two-stop strategy, which we thought was the best direction to take. But, all weekend long we were suffering from a lack of pace and we were really hurt by that during the race. I don't think we could have done much better today."
Race news
Nico Rosberg admitted that his grid penalty altered the approach to race strategy in France. "Even if I'd made it into Q3, I was going to be more or less last on the grid anyway, so it does make things quite different. We needed to think about trying to pass people and not having so much under steer when I was running behind cars, so that I could try to pass into the Adelaide hairpin. You have to compromise your qualifying for that. It was never going to be easy."
Team news
Williams co-owner and director of engineering Patrick Head did not pull any punches about the team's lack of speed at Magny Cours. "Obviously that was a very mediocre performance," he said. "From here we must go away, try to understand our mistakes and put them right. We want to come out fighting at Silverstone and I am sure that we can do better there than we were able to do here."
Did you know?
Kimi Raikkonen's pole position at Magny Cours was the 200th for Ferrari. The Finn narrowly beat team-mate Felipe Massa to the honour as the Maranello cars filled the front row of the grid. Raikkonen looked comfortable in the race until he suffered a broken exhaust, allowing Massa through to take his third victory of the year. The Brazilian now leads the drivers' championship with 48 points to Robert Kubica's 46 and Raikkonen's 43. It is the first time that a Brazilian has led the championship since the late Ayrton Senna in 1993 - although that season's championship was eventually won by Williams driver Alain Prost.