Renault's Fernando Alonso stormed to his second win in a row at the Japanese Grand Prix on Sunday while McLaren's championship leader Lewis Hamilton plunged from first to last and failed to score.
Hamilton finished 12th after starting on pole, with Ferrari rival Felipe Massa battling to eighth in a wild Fuji race to close the gap on the Briton to six points with two races remaining.
The Formula One title rivals both received drive-through penalties, Hamilton for cutting across Kimi Raikkonen's Ferrari and causing mayhem behind him in a mad dash to the first corner.
Massa was similarly penalised after the Brazilian collided with Hamilton on lap two, forcing the McLaren to spin and leaving the Briton in 18th.
"I made a mistake at the first corner and I paid for it," Hamilton told reporters. "Then Felipe hit me off. I left room on the apex of turn 11 but he hit me pretty hard.
Hamilton, who won in Japan last year before allowing Raikkonen to make up a 17 point deficit over the final two races to take the title, said his championship hopes had not suffered serious damage.
"I don't think it makes any difference," said the 23-year-old. "I lost one point today which is I guess damage limitation. We'll move on to next week.
"We'll still be as competitive and we are going to make sure we win the last two races."
OUTSIDE CHANCE
BMW-Sauber's Robert Kubica finished second to boost the Pole's outside chances of the championship, while Raikkonen's third place ended his title defence.
Hamilton has 84 points with Massa on 78. Kubica has 72 with only races in China and Brazil left.
"It's completely unexpected," said Alonso, a surprise winner in Singapore two weeks ago for a team who started the season struggling to score points.
"I can't believe it. Anything is possible now in the last two races," added the double world champion, who had started fourth.
Raikkonen, who started alongside Hamilton on the front row, earned Ferrari six points, lifting them back above McLaren in the contructors' race. Ferrari have 141 to McLaren's 135.
Renault's Brazilian rookie Nelson Piquet finished fourth with Toyota's Jarno Trulli taking fifth at the Japanese team's home circuit in front of the Toro Rossos of Sebastien Bourdais and Sebastian Vettel.
Japan's only Formula One driver Kazuki Nakajima was 15th in his home debut for Williams.
