McLaren's Lewis Hamilton won a chaotic and thrilling Belgian Grand Prix to seize back the Formula One championship lead from Red Bull's Mark Webber on Sunday.

Hamilton's victory, despite a near-miss with the barriers in the challenging conditions ranging from dry to wet, lifted him three points clear of second-placed Webber at the top of the standings with six races remaining.

"It was a great weekend, and very tough racing," said the Briton.

The success, his third of the season, contrasted to teammate and reigning world champion Jenson Button's misfortune on a sweet and sour day for the British team and their two world champions.

Vettel was handed a drive-through penalty for causing a collision and then plunged further back through the field after tangling with Force India's Vitantonio Liuzzi and puncturing the left rear tyre.

The German ended up 15th and out of the points for the third time this year.

Webber, winner of four of the 13 races so far this season, had been on pole position but suffered a terrible start on an afternoon where the fickle Spa weather played its hand to full effect and the safety car was twice deployed.

"Lewis deserved the win, he did a good job," the Australian said.

Poland's Robert Kubica finished third for Renault, losing second with a pit stop error but still taking a morale-boosting result for a team who this time last year became embroiled in a major race-fixing scandal that led to a suspended permanent ban.

Hamilton has 182 points to Webber's 179 and Vettel's 151. Button is on 147.

Button, running behind Hamilton in a McLaren one-two at the fast and flowing circuit, was shunted out of the race by Webber's young German teammate and title rival Sebastian Vettel on the 17th of the 44 laps.

"I thought I was doing a good job of keeping my position and fairly. I don't know what Sebastian was doing," said Button of his incident.

"It's a massive blow, I'm really disappointed. I felt that under the difficult conditions I found grip better than others."

Ferrari's Fernando Alonso, fifth in the standings, retired after an incident-filled afternoon. He collided with Brazilian Rubens Barrichello on the opening lap and dropped to 20th place.

The debris from that incident, apart from ending Barrichello's 300th race without the Williams veteran completing a lap, brought out the safety car.

The Spaniard pitted for a new front wing and fought his way back to eighth but finally crashed out six laps from the end when he spun and hit the barriers between Les Combes and Rivage.

The Ferrari was stranded on the track, again bringing out the safety car.

Brazilian Felipe Massa finished fourth for Ferrari, ahead of Germany's Adrian Sutil in a Force India.

Seven-times world champion Michael Schumacher, who had started in 21st place after a 10-place penalty for an incident with Barrichello at the previous race in Hungary, finished seventh at his favourite circuit.

The 41-year-old former Ferrari ace tangled twice with Mercedes teammate Nico Rosberg, their cars touching once, before the younger German grabbed sixth place.