Sebastian Vettel has extended his lead in this year's drivers' championship after finally winning on home soil.

But the defending triple world champion had to survive several spells of intense pressure to steer his Red Bull to victory in the German Grand Prix.

The 26-year-old German, who also had never won a race in the month of July, came home narrowly ahead of fast-closing Finn Kimi Raikkonen and his Lotus team-mate Romain Grosjean of France.

Vettel's win was his fourth this year and the 30th of his career and it lifted him 34 points clear of nearest rival, Spaniard Fernando Alonso of Ferrari, in the drivers' championship.

"It's unbelievable," said Vettel.

"Kimi was pushing very close in the end, but I was pushing in every lap except from the ones with the safety car."

Vettel's win means that in the constructors' series, Red Bull lead with 250 ahead of Mercedes on 183.

Raikkonen, who closed within a second of Vettel at the end as he stretched his record run of points-scoring races to 26, said: "My radio only worked in one part of the circuit and unfortunately today there was quite a lot to discuss."

Grosjean finished third to grab his first podium finish in five races.

Alonso came home fourth ahead of Britons Lewis Hamilton of Mercedes and Jenson Button of McLaren with Australian Mark Webber seventh in the second Red Bull.

Hamilton started from pole, but fell back and struggled with his tyres before fighting back in the closing stages with some fine passing moves.

Vettel became the first German to win a German Grand Prix at the Nurburgring in the history of the Formula One world championship.

After the drama of four exploding tyre blowouts in last Sunday's British Grand Prix, the race was run without similar incidents other than when an errant wheel flew off Webber's car during a pit-stop and struck a tv camerman, Paul Allen, in the back.

He was being kept in hospital for observation.

The next contest is the Hungarian Grand Prix on July 28.