Well on his way to becoming the sport's youngest world champion, with five wins in 10 races, the 23-year-old Spaniard was relaxed and carefree after Friday's practice at Silverstone.

With a 24-point lead over McLaren's Kimi Raikkonen [Images], and eight races to come after the weekend, Alonso is in no immediate danger of being overtaken.

"I'm having fun being top," he said. "I'm comfortable, even if something goes wrong I will stay in first position. If they have more problems, more engine troubles or more tyre problems it will be too late for them to recover."

Raikkonen is the favourite to win on Sunday while Alonso has said that he expects it to be one of Renault's toughest challenges of the season.

But even when he has been up against it, the Spaniard has still managed to bring home vital points as in Monaco where he nursed his car to fourth place despite the tyres deteriorating before his eyes.

He has made one mistake, in Canada [Images] where he hit the wall while leading.

Raikkonen's dramatic last lap tyre failure while leading the European Grand Prix at the Nuerburgring in May handed the Spaniard victory on a plate and he did not rule out a similar stroke of luck at Silverstone.

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"This track is always difficult...this weekend is a defensive race for us," he said.

"It's up to the others, they have the best car for here, but they have to win and they can't make any mistakes."

Drivers make their own luck and successful ones somehow acquire a momentum that can be hard to break, as Ferrari's [Images] seven times champion Michael Schumacher [Images] has found over his years of domination.

"A driver gets the ball rolling and everything behind him," said Ferrari's technical director Ross Brawn, comparing Alonso's position to that of Schumacher.

"It's not the team's intention to do that, but they get this momentum going and they achieve a result. He (Alonso) has the momentum at the moment and he's doing a very impressive job, but it doesn't stop us trying to beat him.

"We saw very strange circumstances when he didn't score any points in North America. That could happen here and the situation could change," he added.

Williams technical director Sam Michael agreed.

"He's definitely favourite for the championship and the only guy that's going to give him trouble is Kimi," he said. "It just depends on what kind of reliability he has."

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