Jenson Button thrust himself back into Formula One world title contention with a faultless pole-to-flag Belgian Grand Prix victory after avoiding the first-corner chaos that accounted for four drivers.

Championship leader Fernando Alonso was the biggest casualty, ending his run of 23 consecutive races in the points, along with McLaren's Lewis Hamilton.

The accident was instigated by Lotus' Romain Grosjean, and not for the first time this year on lap one, whilst Sauber's Sergio Perez was also forced into retirement.

Button's 14th career triumph means he is still 63 points adrift of Alonso, but the 32-year-old McLaren star cannot be discounted after finally finding some form of late.

Reigning champion Sebastian Vettel, who had started 10th after a poor qualifying by his and the team's standards, finished second to close the gap to Alonso to within a race win at 24 points.

Lotus' Kimi Raikkonen found himself on the podium for the sixth time this year and is 33 points down in the standings in fourth, one point behind Mark Webber who was fifth in the race.

A delighted Button, interviewed by the legendary Belgian racing driver Jacky Ickx on the podium, said: "I still can't get used to this - talking on the podium it's quite strange.

"But this circuit is so special to most drivers, the way it flows and the history, so to get a victory here is very special in what has not been an easy year for me.

"We can enjoy this for a little while before we head to Monza where we can hopefully do the same."

Last year's winner Vettel, after his problems in qualifying, said: "The start was not so good, and after the first corner where a lot of cars went off it was pretty crazy.

"We made the right call to stay out (rather than pit a second time), and we picked up pace.

"So after a poor start to the weekend it was good to come back and I had a lot of fun racing a lot of people."

Raikkonen, who experienced a number of issues with his car in the race, said: "It was not the easiest day for me and the team.

"The car was not exactly as to our liking, but we got some good points for myself and the team."

The stewards face a busy afternoon as they are investigating a number of incidents, including the first corner smash and the jump start by Maldonado.

Also on their agenda is a sharp manoeuvre by Michael Schumacher in front of Vettel as he entered the pits and two unsafe releases involving Caterham's Heikki Kovalainen and Webber.