Defending world champion Sebastian Vettel threw the battle for this year's Formula One title wide open on Sunday when he cruised to a supreme victory in the Japanese Grand Prix.

The 25-year-old German, who won in Singapore only two weeks ago, became the first man this year to score back-to-back wins as he slashed Fernando Alonso's championship lead to just four points with five races left.

Alonso, of Ferrari, was eliminated from Sunday's contest when he was hit by rival Finn Kimi Raikkonen's Lotus at the first corner and suffered a puncture. The fuming Spaniard refused to speak to media afterwards.

Despite the carnage behind him Vettel was left out in front, on his own, and raced to a luxurious triumph, the 24th of his career, a feat that drew him level with the legendary Argentine Juan-Manuel Fangio in the record books.

"Woo-hoo! Yes baby, Yes baby... unbelievable!" screamed Vettel over his team radio on his slowing-down lap, after taking a big step forward in his pursuit of a third consecutive world title.

He came home comfortably clear of Alonso's Ferrari team-mate Felipe Massa with local hero Kamui Kobayashi third for Sauber, a result that made him only the third Japanese driver to score a podium finish in Formula One.

Massa's podium finish was his first in 35 races since the 2010 Korean Grand Prix, a feat that may help retain his seat in 2013 -- but was overshadowed by the huge roar from the capacity crowd that greeted Kobayashi's finish.

Jenson Button finished fourth for McLaren ahead of his Mercedes-bound team-mate Lewis Hamilton, with Raikkonen sixth behind the two Britons.

Nico Hulkenberg of Force India came home seventh ahead of Pastor Maldonado of Williams and Australians Mark Webber of Red Bull, who was involved in the first corner accidents after starting second, and Daniel Ricciardo of Toro Rosso.

Retirement-bound seven-time champion Michael Schumacher, 43, finished 11th, just failing to score a point after starting from the back of the grid for Mercedes.

On a warm and dry day with a track temperature of 32 degrees Celsius (90 Fahrenheit), Vettel made a perfect start and drew clear of the pack -- but behind him, it was mayhem.

Kobayashi, inspired by his bid to become the first Japanese driver to claim a home podium finish since Aguri Suzuki in 1991, shot forward to snatch second as the lights went out while the luckless Alonso was heading towards elimination.

In a thunderous burst of collisions, similar to the start of last month's Belgian race, both Alonso and Nico Rosberg of Mercedes were knocked out as innocent victims of collisions while Webber was also forced off the circuit, but recovered.

Re-runs of the action showed that Raikkonen rammed into Alonso and punctured his left rear tyre, in a bitterly frustrating incident for the Spaniard.

Webber was shunted by Romain Grosjean of Lotus and Rosberg was the victim of a similar assault from Williams' Bruno Senna. Both offending drivers were given drive-through penalties.

When the safety car withdrew after three laps Vettel streaked away in front followed by Massa and Sauber's Sergio Perez, who will replace Hamilton at McLaren next year and raced with great vim before making a mistake and spinning out.

By lap 15, Vettel held a large 11-second lead ahead of Massa, Perez and Hamilton before the leaders began their pit-stops.

Then the German, revelling in the performance of his Red Bull car, simply romped away from the field. By lap 33 he was 15 seconds clear of Massa with Kobayashi third and the two McLaren men, led by Button, in pursuit.

Button closed to conjure up the prospect, for McLaren, of a podium finish, but Kobayashi, inspired by his fans, held on to enjoy the finest afternoon of his Formula One career and boost his own hopes of staying with Sauber next season.