Lewis Hamilton mastered wild and wet racing conditions to score a runaway victory at the British Grand Prix and throw the Formula One drivers championship wide open.

After he failed to collect a single point from the previous two races in Canada and France, Hamilton's title hopes would have been in trouble if the same had happened in front of his home fans at Silverstone on Sunday.

But the 23-year-old British driver, who last year squandered a 12-point lead with two races left in his rookie season, stayed in control on a rain-soaked track that plagued his rivals. Many were unsure which tires to use, and repeatedly spun or veered off the circuit.

Hamilton led from the fourth lap in his McLaren to win his first British GP and take the lead in the overall championship.

Hamilton lapped all but two of the field and finished more than a minute ahead of Nick Heidfeld's BMW Sauber. Rubens Barrichello was third for his first podium in four years and Honda's first of the season.

"It is by far the best victory I've ever had," Hamilton said after waving to the 90,000 fans who gave him a standing ovation following his 68.5-second victory.

"The conditions were bad and as I was driving I thought, 'If I win this, it will be the best race I've ever done'. On my last lap, I could see the crowd starting to rise to their feet, and I was just praying, praying, praying I could get the car round.

"It was so extreme out there. I was having big problems with my visor. I couldn't see a thing."

Hamilton's third victory of the season gives him 48 points. He is tied with Ferrari drivers Felipe Massa and Kimi Raikkonen, but leads the championship chase based on his better finishes in the other races.

Massa spun at least five times in the race and finished last in 13th, failing to pick up a point. Raikkonen was fourth.

In a drivers championship that is neck-and-neck at the halfway stage with 10 races to go, Robert Kubica is two points behind the leaders with 46. He dropped out after spinning his BMW Sauber off the circuit during the 39th lap.

There was nothing close about Hamilton's victory. But after the experience of nearly winning last year, he was saying little about his chances this season.

"It's a work in progress we're doing a good job and I just want to keep on building on it," Hamilton said. "I would have been happy with a point."

Barrichello had been in the points only twice this season, placing sixth at Monaco and seventh in Canada.

"It's fantastic. I've never lost the belief I have in me," said the Brazilian, who has nine F1 victories in 15 years on the circuit, longest among the 20 drivers.

"I've this great feeling. It's like I'm young, I just love the sport. I just love the speed. I can't live without that."

Hamilton, starting fourth on the grid, provided an eventful beginning to the 60-lap race when he burst past both Red Bull's Mark Webber and Raikkonen at the beginning.

He also tried to overtake pole-starter and McLaren teammate Heikki Kovalainen on the inside of the first bend, but the Finn responded and the two McLarens almost touched.

Also on the first lap, Massa, Webber and Kazuki Nakajima went into a spin but rejoined the race. David Coulthard, in his last British GP before he retires at the end of the season, and Sebastian Vettel both slid into the same gravel area at the sharp left-hand Priory bend and were out of the race.

Seven of the 20 starters failed to finish.

Two points ahead in the drivers standings at the start of the race, Massa failed to recover from his early spin and slipped to the back of the field, more than a minute behind the leader after only 13 laps. The Brazilian finally overtook Nico Rosberg on the 17th lap and then Giancarlo Fisichella to move into 15th, but he had more trouble later in the race and was lapped twice by the leader.

"This Silverstone weekend is one to be wiped out," Massa said. "On Friday I had an accident, yesterday there was the problem in qualifying and today a series of mistakes at all levels. Today I could hardly keep the car in a straight line and it was always difficult to drive."

At the front, Hamilton overtook Kovalainen on the fourth lap with a bold move going into the fast Stow right-hander, powering ahead and then timing his braking to keep the lead.

The British driver then opened up a 6-second gap only for Raikkonen to cut the lead to less than a second when they both came into the pits for the first time on lap 22. Although Hamilton changed tires, he kept the same intermediate style while Raikkonen made no change, which proved to be a mistake.

Although Hamilton left the pit line just ahead of the Finn's Ferrari, he began to pull away and opened up a lead of almost 25 seconds halfway through the race.

From that point, no one got near him, and Hamilton gave British racing fans the victory they had been waiting for.