Sebastian Vettel downplays Friday performance after topping practice times

The Red Bull driver, who could become a double champion this weekend, posted the quickest time in the afternoon session on Friday, outpacing Ferrari's Fernando Alonso by two tenths and McLaren's Lewis Hamilton by over seven.

Despite his strong start to the weekend, Vettel denied Red Bull had the advantage in Singapore.

"I wouldn't call it advantage, I think it looked pretty tight," said Vettel. "It depends where and when and who was out, we have to wait and see.

"It is Friday. Tomorrow is Saturday and we worry about FP3. Then qualifying and then the race. The feeling in the car was alright. We have to see. We have to look how the others were, do our homework tonight and then see what we can do tomorrow.

"We did work quite a bit, the car was good though. The baseline was not too bad, I think we can still have to make a good step overnight so now we see what the others did and we will do our homework."

The German said it was still hard to see who his main rivals will be this weekend, but admitted Ferrari was looking very strong.

"I don't know. I didn't have as much time as you to look at the times so I was busy when I was on the track, but surely Ferrari looked quite competitive, Felipe as well at some stage, so we need to see.

"Jenson [Button] didn't have the best day today so we see what happens tomorrow."

Team-mate Mark Webber was fifth fastest.