Rosberg thought penalty had ruined race

The Williams driver was given a ten-second stop-and-go penalty after he was forced to pit for fuel when the pitlane was closed when the safety car was on track.

The controversial rule, which is likely to be changed for next year, also caused BMW Sauber's Robert Kubica to be given a penalty, the Pole having to pit in order not to run out of fuel.

But Rosberg, leading after the safety car period, took full advantage of the time it took the stewards to penalise him to build a big lead and return to the track to finish in a career-best second.

The German admitted he was annoyed by the penalty.

"When I had to come in, I saw the safety car out. The crew said 'come in this lap'," said Rosberg. "Every single time it is exactly the same thing (with the safety car rules).

"I was really annoyed as I thought that was it, the end of it.

"But then I saw I was able to pull a gap afterwards even after the stop. We had a good chance here this weekend and everything went our way which is great for me and the team."

Rosberg said he had to push as hard as in qualifying in order to climb up following a slow start.

"I had a little bit of a difficult start on the dirty side and dropped behind Jarno. He was heavy on fuel, so I had to get by him. The only chance was at Turn 1 as Turn 7 so bumpy it was impossible to outbrake someone.

"It took some time and even then had quite a hairy moment as I locked up everything but came through. Then drove like I was in qualifying and I was able to break away from group."

Rosberg's previous best result was a third place at the Australian Grand Prix earlier this season.

Teammate Kazuki Nakajima also scored in Singapore after finishing in eighth position.