Mark Webber cruised to his fourth win of the season to reclaim the lead in the Formula One drivers' championship following a chaotic Hungarian grand prix.
A safety car deployed to clear debris on the Hungaroring after 14 laps caused mayhem from which Webber ultimately emerged the winner ahead of Ferrari's Fernando Alonso and Webber's Red Bull Racing team-mate Sebastian Vettel.
With Lewis Hamilton's McLaren suffering a gearbox failure on lap 24, Webber has now reclaimed the lead of the championship by four points from the Briton, with Vettel a further six points down.
With just a fifth of the 70-lap race gone it appeared as if we were in for a processional run to the finish on a circuit where overtaking is virtually impossible. But debris on the track from Vitantonio Liuzzi's Force India sparked penalties and retirements.
It brought the safety car into play, with Vettel receiving the call just in time to pit as he cut across the kerb running alongside the entry to the pit lane. With the exception of Webber, running third at the time, the bulk of the field pitted to change tyres.
But as Mercedes's Nico Rosberg pulled out on to the pit lane one of his tyres worked loose, initially rolling and then bouncing its way through the other pit crews, with one Sauber mechanic just avoiding being hit. Then Robert Kubica was released too early by his crew and he ran into the side of Force India's Adrian Sutil just as the German was about to pull into his pit entry box.
The damage was too great for Sutil to continue, and although Kubica was soon sent on his way again he received a 10-second stop-go penalty for an unsafe release from the pits. Rosberg trundled down to the end of the pit lane on three wheels and, with his crew unable to retrieve him, was forced to retire. The stewards are to investigate both incidents.
Hamilton jumped Felipe Massa in the pit stops and Ferrari were forced to back their drivers up, which allowed the McLaren driver to move up to fourth, while his teammate Jenson Button, who had made his stop just before the safety car was deployed, had moved up to 10th from 14th following a poor start.
Then as the safety car was poised to return after two laps on track, Vettel allowed Webber to open up a considerable margin. With Webber needing to stop, the Red Bull team were attempting to get him off to a flyer in the hope he could then eke out a lead, take on tyres and so secure a one-two. Vettel, though, allowed the gap to Webber to exceed 10 car lengths, which is against the regulations, resulting in him being handed a drive-through penalty.
When he served his punishment at the end of lap 31, he clenched his fists in anger as he drove through the pit lane. He came out between the two Ferraris, and spent the remainder of the race staring at the back of Alonso's exhaust with no opportunity to pass in the final 30 laps.
Out in front Webber stayed out on the super-soft tyres for 43 laps, building a 23-second cushion to Alonso, enough to allow him to take on fresh rubber, retain his lead and stroll to victory. Alonso held off Vettel for second, followed by Massa in fourth and Renault's Vitaly Petrov enjoying his best result for the team with fifth.
Williams' Nico Hülkenberg was sixth and Pedro De La Rosa ended his points drought for Sauber with seventh. Behind Button in eighth was the second Sauber of Kamui Kobayashi, while Williams's Rubens Barrichello claimed the final point.
That was after a pass on Michael Schumacher in his Mercedes on lap 66 in which he was almost pushed into the wall along the pit straight, another incident the stewards are to investigate.
After the race, Vettel said: "I didn't understand what was going on and why I was penalised. At the restart I was sleeping. I was probably relying too much on the radio, I lost the connection and didn't hear anything. I didn't see the lights, whilst Mark also usually drops back and tries to dictate the pace.
"But then I saw a big gap to myself, I saw the safety car pulling in and lost out, then I had the drive-through [penalty]. It's been explained to me why, but I still don't understand it. We're pretty unlucky because otherwise it would have been a walk in the park. I should have won, but in the end I was third and I am very disappointed."
Webber was more satisfied with his afternoon. "We had the safety car, and I had to go off strategy to pass Fernando. But in the end I knew once I had the primes [harder tyre] on, that would be it to the end," he said.
"It was a bit of a gift, but I've not had many of them, so an incredible day for the team. The victory is good, irrespective of what happens to your rivals. It's nice to have more points than anybody else, but we're not getting ahead of ourselves as there are some big events coming up."
Asked if second was the best he could hope for, Alonso replied: "Yeah, I think so. But even if we have five or six more gifts like this, it won't be enough. It was a good race, with the start superb, passing Mark, and then very stressful moments with the safety car.
"We found ourselves second. Mark was very quick, able to do 40 laps on a set of tyres that should not have been the case."