Sebastian Vettel says he is "surprised" to have taken pole position for the Singapore Grand Prix by such a big margin.

Vettel looked dominant throughout qualifying, building on the fantastic pace shown in final practice, to blitz his rivals.

In the end both his runs in top-ten shootout would have been good enough to give him his first pole with Ferrari - and Ferraris first for 61 races - but still he did improve on his final lap.

Indeed he was the only man to break the 1m 44s bracket, posting a 1m 43.885s lap, to leave him 0.543s up on former Red Bull team-mate Daniel Ricciardo.

"A proper one I would say. Unbelievable, I know it is only Saturday and obviously the main job is coming tomorrow but I had to enjoy the moment when I heard that we had made it. It was looking pretty good right from the off-set of qualifying and actually from this morning [FP3] to be fair. And then it was just... the car was fantastic to drive - it just got better through qualifying," Vettel said.

"We got the maximum today. I am surprised by the margin but I just think it came together. I really had a near perfect lap at the end. I was very happy with the laps I had today, especially the last one.

"Around here it is such a long tricky lap and so easy to just go in a little bit too deep or in too far and push it a little bit too much. It just seemed to come in the end and I was very happy that I made it to the finish line because it felt like a good lap and it was a good lap in the end.

"Very happy."

Meanwhile, Vettel added that he thought Mercedes were "sandbagging" in practice when they were off the pace, although as it turned out fifth and sixth was a good as they could do.

"I don't know [why they are not as strong as usual], it's a surprise. I thought they were sandbagging yesterday and also this morning because there is no doubt they have the strongest package," he continued.

"They have a very good car, a very good power unit, which we know, and usually that puts them up there very high and makes them difficult to beat. I don't know, they must have some issues and not feeling comfortable at all with their degradation, I think. I wouldn't rule them out for tomorrow. It's not the easiest circuit to overtake, but if you have the pace you can close in."