Lewis Hamilton led from start to finish to capture his second victory of the season at the Singapore Grand Prix.

The McLaren driver had downplayed his chances in the build-up to the weekend but secured a surprise pole in yesterday's qualifying.

He then carried that form into today's race under the lights at the Marina Bay street circuit and victory rarely looked in doubt for the reigning world champion with only Red Bull's Sebastian Vettel briefly threatening his lead.

Toyota's Timo Glock secured a career-best second while last year's winner in Singapore Fernando Alonso took third in his Renault.

"It was a very, very tough race," said Hamilton. "I got a good start and I just managed to bridge a big enough gap.

"I have to say a big thank you to my team for doing a great job as always."

Vettel had to settle for fourth after his challenge for first ended when he was hit with a drive-through penalty for speeding in the pit-lane. There was added disappointment for Red Bull as Mark Webber failed to finish the race when he crashed out due to a braking problem.

Jenson Button produced a good performance after a disappointing qualifying session to finish fifth and actually extended his lead in the championship.

The 29-year-old had started 11th today but drove well throughout to finish one place ahead of Brawn GP team-mate and title rival Rubens Barrichello.

Button leads the Brazilian by 15 points with three races of the season remaining.

McLaren's Heikki Kovalainen claimed seventh place while BMW Sauber's Robert Kubica took eighth.

Hamilton was straight out of the blocks and shot clear of the field while Williams' Nico Rosberg moved ahead of Vettel to take second.

Renault's Romain Grosjean was the first casualty of the race when he was forced to return to the pits early in the race due to a problem with his breaks.

Hamilton, meanwhile, continued to increase his lead at the front as he set the fastest time in lap 10 to climb into a 2.2 second lead ahead of Rosberg.

But Rosberg's challenge was to come to an end when the German made his first pit stop in the 19th lap but was too quick exiting the pits and bounced over the pit-exit line, resulting him being hit with a drive-through penalty.

Force India's Adrian Sutil and BMW Sauber's Nick Heidfeld, who had started from the pitlane after being relegated to the back of the grid when his car was found to be underweight following qualifying, were then involved in a collision that ended both their races.

That brought the safety car out and Button profited, re-emerging in eighth after he, Alonso and Kovalainen had made a pit stop,

Midway through the race, Vettel had begun to make his challenge for the lead and after 35 laps he was just eight tenths of a second behind Hamilton, waiting to pounce on any error.

But instead it was the German who committed a costly error when he entered the pits for his final stop on lap 40. Vettel re-emerged in seventh place but was found to have driven too fast in the pit-lane and was hit with a drive-through penalty as a result.

From then on the race was Hamilton's to lose and though Glock had climbed up to second he was over eight seconds behind the race leader with three laps remaining.

As a result Hamilton calmly drove out the remaining laps to comfortably claim the 11th victory of his career.