Mark Thompson, Getty Images
Lewis Hamilton, center, celebrates Sunday's victory in the British Grand Prix with his teammates.

SILVERSTONE, England — 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 he 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.

WATKINS GLEN: Scott Dixon's bid for a fourth straight victory on the road course at Watkins Glen ended Sunday with an uncharacteristic mistake that gave Ryan Hunter-Reay the opening he needed to earn his first IndyCar Series victory.

Dixon, preparing to make a run at leader Darren Manning after a long caution period, spun out under yellow and was hit from behind by contender Ryan Briscoe. That gave the runner-up spot to Hunter-Reay, who easily passed Manning on the restart and drove away with the fourth series win for Rahal Letterman Racing.

It is the third open-wheel victory for Hunter-Reay, a Texas-born driver who won twice while driving in the now-defunct Champ Car World Series.

"It's huge," Hunter-Reay said after doing some celebratory burnouts. "I'm an American boy ... and this is a real Fourth of July weekend celebration."

It was a strange finish to a race that went the first 40 laps on the 3.4-mile, 11-turn circuit with only a couple of minor incidents and wound up running under caution for most of the last 20 laps because of a series of crashes and spinouts.

Dixon, trying to become the first IndyCar driver to win four straight races on any track, appeared to be in position, with only the vulnerable Manning — whose best previous finishes were a quartet of fourths — ahead of him as the field was about to get the green flag with 12 laps remaining

The series leader, winner of two races this season, including the Indianapolis 500, said he was trying to get some heat into his front new front tires after pitting on lap 41. He shot forward and, suddenly, his Chip Ganassi Racing Dallara spun.

"I was a complete idiot," an obviously embarrassed Dixon said after getting restarted and finishing 11th. "We lost a lot of valuable points today. I feel more down for Briscoe and the boys."

Briscoe, who started from the pole and led a race-high 37 laps, had to pit for a new nose after hitting the stopped Dixon. He finished 12th and was disappointed, but not angry.

"It's unfortunate," Briscoe said. "I can only imagine how Scott's feeling right now. I just wish he could have messed up and not gotten me involved. ... I think we had a real shot. It would have been a real good fight between me and Dixie down to the finish line."

The last seven laps were run under green and Hunter-Reay pulled steady away, beating Manning to the finish line by 2.4 seconds. Tony Kanaan, who crashed in the morning practice and drove the race with a sore left wrist, wound up third, followed by Buddy Rice, Marcio Andretti and Bruno Junqueira.