Hamilton ascribes much of his overtaking skills to his early experience in an uncompetitive kart. File photo: Jens Meyer / AP

Hockenheim, Germany - Lewis Hamilton dug deep into his past to explain Sunday's stunning German Grand Prix victory and came up with a 'four-poster bed'.

The four-times Formula One world champion had never before won a Grand Prix from lower than sixth on the starting grid but at a wet Hockenheim, he steered his silver Mercedes from 14th to first. That was only the 12th time that a driver had started that low and won.

The achievement, helped by chaos around him and Ferrari title rival Sebastian Vettel crashing out from the lead, left the new championship leader struggling to contain his emotion.

"It's very reminiscent of how I started out," he explained to reporters at Hockenheim, whose present layout has been likened to a glorified go-kart track by those who miss the bygone blast through the forest.

"The kart that I had was really, really old and had been owned by about five different families. My dad spent the little bit of money he could to shave it down and respray it and made it as brand-new as it could be.

"He would call it 'the four-poster bed'. I would have to start at the back and wiggle my way through the more experienced and faster karts. And that's where I learned to do it. That's what I was best at doing."

Hamilton, age 10, racing the 'four-poster bed' in 1995. Picture: LewisHamilton.com

 Hamilton is an ace in the wet, just as Michael Schumacher was before him, but on Sunday he was master of everything thrown at him. Already up to fifth with 14 laps gone, picking off almost a car a lap, Hamilton proceeded to take great chunks of time out of his rivals as the rain fell and the tyre strategy played to his advantage.

He also had the presence of mind to follow his instincts rather than listen to the panicked messages from the pit wall that almost led him to pit and risk undoing all his good work in the blink of an eye. On such moments are championships won and lost and Hamilton, now 17 points clear of Vettel, made the difference.

As the title battle enters the second half of the season, the lead has gone back and forth and nothing can be taken for granted. Both teams have made mistakes, Mercedes with glaring strategy errors and Vettel - as on Sunday - under pressure and in the heat of battle.

Hamilton and Vettel have four wins apiece, one retirement each and Vettel is ahead 5-4 on pole positions. It is debatable which of the two has the faster car and small margins are proving crucial. As Sunday showed, anything can happen and there is everything left to play for.