Formula One championship leader Lewis Hamilton promised to come out fighting at this week's Japanese Grand Prix after a freak technical mishap in Singapore opened the door to his rivals.

The Mercedes driver failed to finish a race for the first time in more than a year after a simple metal clamp came loose in his engine, leading to a sudden loss of power.

Nico Rosberg finished fourth to lie 41 points behind Hamilton in the standings, while Sebastian Vettel won the race to move within eight of the second Mercedes driver.

It capped a woeful weekend for Hamilton, who earlier failed to earn a record-equalling eighth straight pole position and was seeking his eighth win of the year.

While he still enjoys a healthy lead in the standings, any more gremlins in the remaining six races could bring Rosberg and Vettel right back into the title race.

But the 30-year-old Briton said he had been driving well until the technical failure, and vowed to resume his hot run of form when he arrives at Japan's Suzuka circuit.

"It’s still a long way to go and I know I lost some points today, but I was fast and on form and I will make sure I bring that out to Suzuka to fight back," Hamilton said.

He added: "The race was going very well. For me it felt like I was driving at my best in the race. I think I had the pace to win. I did everything."

Team principal Toto Wolff called it a "character-building" weekend after Vettel earlier loosened Mercedes' 23-race hold on pole position, demonstrating their lack of pace.

The slow corners and short straights of Singapore do not play to the strengths of the Mercedes engine, but Wolff said the race was a warning-shot to his team.

"There were times in the race when the pace looked okay but the guys in front were managing their tyres, too, so we must be realistic about our level of performance at this circuit," he said.

"Now we need to analyse everything precisely, understand the wrong turn that we took this weekend to learn the right lessons -- and then close this chapter.

"One bad weekend doesn't overshadow our achievements so far this year but we know that there is no room for complacency after a weekend like this. We will aim to hit back strongly next weekend in Suzuka."
Source: AFP