Vettel wins in Japan after Alonso exit

Red Bull's Sebastian Vettel won the Japanese Grand Prix and blew the Formula One championship wide open with five races remaining after Ferrari's Fernando Alonso spun out at the start.

Alonso's pre-race lead over reigning champion Vettel, chalking up his second win in a row and third of the season, was cut to four points from 29 with the Spaniard in danger of falling behind in South Korea next weekend.

"It was an important step today but there's still a long way," said Vettel after holding aloft the winner's trophy and making the familiar raised forefinger gesture as number one.

"These things happen and obviously you don't hope for those things to happen to yourself," he added of Alonso's exit into the gravel following contact with former Ferrari champion Kimi Raikkonen's Lotus.

"We have so many races, it could happen. We don't know what happens in the next race, it's good to take the points today."

Ferrari's Felipe Massa came second, 20.6 seconds behind Vettel, for the Brazilian's first podium finish since October 2010 with Japan's Kamui Kobayashi delighting his home crowd with third place for Sauber.

Only the third Japanese to stand on a Formula One podium, he was the first since Takuma Sato at Indianapolis in 2004. Only Aguri Suzuki, in 1990, had previously finished in the top three at Suzuka.

"Fantastic, unbelievable," he said, sharing a podium with Vettel for the first time since their Formula Three days and addressing the fans in Japanese.