A post-race stewards investigation further reduced Lewis Hamilton's championship lead following the Japanese grand prix.

Ferrari's Felipe Massa finished the Fuji race eighth, but he was promoted to seventh when stewards applied a 25-second penalty to Sebastien Bourdais' finishing time for their collision at the end of the pitlane.

With Hamilton out of the points following a pitstop and penalty for his botched first corner, it means Brazilian Massa closes to within five points of the Briton with just two races to go in 2008.

"I made a mistake and I paid for it," said Hamilton, referring to the early incident with Kimi Raikkonen.

Massa was also penalised at Fuji, for an overtaking move that punted Hamilton into a spin. Hamilton believes his own penalty for pushing Raikkonen wide was less deserving.

"We both got the same penalty but I didn't hit anyone and he did, so I guess that's just the name of the game," the 23-year-old said.