Lewis Hamilton has warned his McLaren Mercedes team against complacency after a tactical blunder almost cost him victory in the German Grand Prix.

McLaren boss Ron Dennis was forced to apologise to Hamilton for telling him to stay out on the Hockenheim track while most of his rivals made pit stops for new tyres and fuel during a prolonged safety car period.

The safety car was deployed following an horrific crash which destroyed the Toyota of Germany's Timo Glock, and when Hamilton was eventually brought in from the lead he had to fight back from fifth place with 16 laps to run.

The 23-year-old British driver was helped first by BMW-Sauber's Nick Heidfeld having to pit and then by his team-mate Heikki Kovalainen moving over to let him pass.

But Hamilton, who had started from pole position, was forced to summon every ounce of his own supreme driving skill to make inch-perfect overtaking moves on the Ferrari of Felipe Massa and the Renault of Nelson Piquet Jnr before claiming victory.

Hot on the heels of his dominant victory in the British Grand Prix at rain-soaked Silverstone, Hamilton's fourth win of the season gives him a crucial four-point lead over Massa in the title chase with defending champion Kimi Raikkonen a further three points adrift. But Hamilton knew his latest triumph was a close-run thing.

He said: "For sure, we could have done a better job. I'd have much preferred an easy, comfortable afternoon out front.

"What happened made my job a little bit harder but I just told Ron 'that's what you hire me to do. This is what I'm here for'. It's great to see that we have the pace, but we've got a lot of work to do for the rest of the season. We have not to get too far ahead of ourselves."

Piquet took his first career podium in second place after starting from a lowly 17th position on the grid. The Brazilian rookie, who had been under pressure following poor performances earlier in the season, admitted: "It was an incredible feeling. After the safety car left, I knew I was in a very strong position. I just had to push until the end, not making any mistakes."

Massa admitted his car had been no match for Hamilton's McLaren which raced away into the distance from the start.

He said: "We had a difficult car to drive, I don't know why. Lewis pulled away very easily in the first stint and then in the last stint I started to have problems with the brakes. I had so much smoke coming from the car under braking and just lost a lot of performance."

Glock was detained in hospital for observation overnight after his Toyota suffered suspected rear suspension failure which pitched him backwards into the pit wall at high speed.

Toyota team principal Tadashi Yamashina said: "Timo is fine. That's the most important thing."