Lewis Hamilton was stripped of victory following Sunday's Belgian Grand Prix after stewards imposed a 25-second penalty on the McLaren driver.

Hamilton had taken the chequered flag after a dramatic conclusion to the race at Spa but a stewards' inquiry was launched into an incident on lap 42 of the 44-lap race.

Two circuits from the end, Hamilton made a move on entry into the Bus Stop chicane, and collided with Kimi Raikkonen as the pair battled for the lead.

That pushed the Briton on to the run-off area and he resumed in the lead.

He then let Raikkonen through, fearing an instant penalty from the race stewards.

However, on reviewing footage of the race they decided to punish Hamilton anyway.

Raikkonen later crashed out as the wet weather took its toll.

The effect of the stewards' decision meant victory was awarded to Ferrari's Felipe Massa, with Nick Heidfeld (BMW) promoted to second place and Hamilton falling to third.

Hamilton thought he had stretched his lead in the drivers' championship to eight points by finishing first, however, his advantage over Brazilian Massa has now been reduced to two.

A consolation for Hamilton will be that Raikkonen failed to finish, despite leading going into the closing stages of the race, and it looks increasingly like a straight head to head for the title between the current top two in the standings.

McLaren looked to have clinched a fitting triumph to mark the 40th anniversary of their first Formula One victory at this track, under founder Bruce McLaren in 1968.

Hamilton, who started from pole, recovered from an early spin and steadily closed the gap on Raikkonen before the pair engaged in their thrilling tussle for the lead.

With six laps remaining the rain started to slowly fall, and it played into Hamilton's hands.

Within a heartbeat of allowing Raikkonen back in front down the start-finish straight after their Bus Stop collision, Hamilton attacked again, and passed at La Source.

The rain then scythed down and from then on the rest of the lap became a lottery as Hamilton first ran wide, allowing Raikkonen back in front.

But moments later Raikkonen slid off into a wall, out of the race.

Hamilton then tip-toed around the track for the last lap, punching the air when he finally crossed the line.

Massa managed to come home second, with Heidfeld taking advantage of the mayhem to be the third driver across the finish line.

Fernando Alonso took fourth place in his Renault, followed by Sebastian Vettel for Toro Rosso, Kubica for BMW Sauber, Sebastien Bourdais in his Toro Rosso and Toyota's Timo Glock.

Glock was later handed a 25-second time penalty by race stewards after ignoring waved yellow flags at one point late in the race.

That resulted in the German losing his single point, after previously finishing in eighth place, with Red Bull's Mark Webber promoted into the final points-scoring position.