Vettel warns Ferrari no shoo-in for Singapore

Vettel has won four of the nine Singapore races so far, but he dismissed expectations that Ferrari will have the edge over Mercedes at the corner-heavy Marina Bay street circuit.

Vettel trails Hamilton by just three points in the standings, but the Mercedes driver has won three of the last four grands prix - including his crushing victory two weeks ago in Italy.

"In theory it should be a bit better here than Monza but I think it will be close," Vettel told reporters.

"We've seen that it's very close no matter where we go (even on) tracks that (should) definitely suit Mercedes or (should) definitely suit Ferrari."

A Mercedes win would be considered an upset in Singapore, whose 23 corners and lack of long straights tend to play to Ferrari's strengths.

But Vettel said there had been little between Ferrari and Mercedes on tracks of all different types this year.

Asked whether victory on Sunday was vital for his season, Vettel said: "I think it's more important to have the lead after Sunday night in Abu Dhabi (the final race).

"Whatever happens on the way, happens. The target is clear. We have a lot of races, a lot of time to get points, and then we see the count at the end."

As well as his wins in 2011, 2012, 2013 and 2015 in Singapore, Vettel drove brilliantly from the back of the grid last year to finish fifth.

But the four-time world champion said: "It's a big challenge. It's the longest race of the season in terms of duration. It's the toughest one in my opinion for focus and stress.

"It's the sort of race you look forward to the whole season but you don't really want to start, because you know how difficult it is."

Hamilton's phenomenal form in qualifying, with eight pole positions this year, gives Mercedes a good chance. The pole-sitter has won seven of the nine Singapore races so far.

"If we can get the car in a place we're comfortable in, then I think we'll definitely be strong," said the Briton.