Sebastian Vettel may have broken Mercedes' hold on qualifying at the Singapore Grand Prix, but he expects Lewis Hamilton and Nico Rosberg to come strong in Sunday's race.

The four-time world champion streaked to pole position in a time on one minute 43.885 seconds on Saturday, as Ferrari and Red Bull profited from a rare bad day at the office for Mercedes.

Championship leader Lewis Hamilton is the highest placed Mercedes driver in fifth place, but the Briton was nearly a second and a half adrift of Vettel.

Nevertheless, Vettel expects Hamilton – and team-mate Rosberg – to be a threat when the race gets under way.

"It's a surprise," admitted the German. "I thought they [Mercedes] were sandbagging because there's no doubt they have the strongest package this year. They must have some issues.

"But I wouldn't rule them out for [Sunday's race]. It's not the easiest circuit to overtake, but if you have the pace you can come through. So I expect them to be strong."

Vettel heaped praise on the car supplied to him by Ferrari and hopes it continues to enable him to win a third race of the season.

He added: "The car was fantastic to drive, it got better through qualifying and I think we did the maximum. 

"I'm surprised by the margin but I think it just came together. I really had a near-perfect lap at the end.

"I know it's only Saturday and the main job is coming [on Sunday] but I had to enjoy the moment when I heard that we'd made it. It was looking pretty good, right from the off – and from this morning."

Meanwhile, team-mate Kimi Raikkonen – who qualified third – was surprised at his own display more than that of the Mercedes.

"It was quite a good result for the team," said the Finn. "I was not very happy since this morning for whatever reason – so I'm a bit surprised to be in this position after how difficult it felt all day, but it was good.

"We have to do a good job [on Sunday] and hopefully get the two cars on the podium."