Vettel won the Belgian Grand Prix

Defending Formula One champion Sebastian Vettel won the Belgian Grand Prix on Sunday to strengthen his overall lead with seven races remaining.

Vettel started from pole position to win his seventh race of the season and 17th of his career. The German led Red Bull to a 1-2 finish with Mark Webber finishing close behind.

McLaren's Jenson Button started way down in 13th spot, but he caught Fernando Alonso near the end to take third place.

Lewis Hamilton's slim title hopes took a further blow as he crashed his McLaren early on.

Hamilton slipped to fifth in the standings, 113 points behind Vettel, who has a 92-point advantage over second-placed Webber.

Vettel secured pole position for the ninth time in 12 races this season. But he had not won any of the last three GPs in Britain, Germany and Hungary, and only one of the last five heading into Spa, prompting speculation that he was losing his grip on the title.

Vettel's jubilation was evident at ending that winless run as he stood on top of his Red Bull after the race, and pumped his fists in delight.

"What a race!" he told his Red Bull team over the race radio at the end.

The 24-year-old overcame significant tyre wear early on and held off Alonso when the Spaniard was pressuring strongly.

Twenty years after making his F1 debut on the same track, seven-time former champion Michael Schumacher started from last place after crashing during the first lap of Saturday's qualifying session.

The 42-year-old German drove his Mercedes with panache to finish in fifth place behind Alonso.

Tyre management proved a crucial factor in Vettel's win on the 7-kilometer (4.3-mile) Spa circuit — the longest and arguably the most difficult on the F1 calendar.