Formula One world champion Lewis Hamilton won the Hungarian Grand Prix on Sunday to mark McLaren's return to form after a slump of 10 races without success.

It was also the first success for a car equipped with the new KERS energy recovery system.

"It's an incredible feeling to be back here after what seems like such a long time away," said Hamilton. "We've caught up quite a bit but we never really thought we had the pace to win. To get a win, it's amazing".

Brawn GP's Jenson Button had a frustrating afternoon in the Hungarian heat, struggling to get performance out of the car's tyres, and finished seventh after starting eighth.

His unhappiness was only relieved by the retirement of Vettel, his previous closest rival, and seeing the top two places filled by drivers whose title dreams had long disappeared.

Spain's Jaime Alguersuari became the youngest driver to start a Formula One Grand Prix on Sunday at 19 years and 125 days.

The teenager, driving a Toro Rosso, could also boast that he lasted longer than double world champion compatriot Fernando Alonso who started the Hungarian Grand Prix on pole position for Renault but retired after 17 laps.

Kimi Raikkonen, driving the only Ferrari in the race after Brazilian team mate Felipe Massa suffered a serious head injury in qualifying, was second but under investigation by stewards for colliding with Red Bull's Sebastian Vettel at the start.

Ferrari paid tribute to Massa, in intensive care in a Budapest hospital after emergency surgery on Saturday, before the race with a pit board declaring "Forza Felipe, Siamo Con Te" (Come on Felipe, we are with you).

Hamilton's victory, 11.5 seconds ahead of 2007 champion Raikkonen, was the 24-year-old's first since China last October, and 10th of his career. It was his Mercedes-powered team's first podium finish of the year.

"Great job guys," said Hamilton after he took the chequered flag. "This car is so nice to drive. Fantastic. You guys have worked so hard and I'm so glad we could do it."

Australian Mark Webber finished third for Red Bull to go second in the championship, 18.5 points behind Britain's Jenson Button with seven races remaining.