Scott Redding missed the chance to become the first British winner of a motorcycle championship in 36 years as Pol Espargaro won the Japanese Grand Prix to claim the 2013 Moto2 title.
Redding, 20, lost the championship lead to Espargaro in Australia last weekend after missing the race with a fractured wrist.
He was cleared to race on Sunday but crashed out in the first lap.
Espargaro then overtook pole-sitter Mika Kallio for a two-second victory.
The Spaniard now has a 41-point advantage over Redding in the standings with just 25 available at the season-ending race in Valencia on 10 November.
Redding was bidding to become the first British winner of a championship since Barry Sheene in 1977.
This is his final season in Moto2 before he moves up to MotoGP next year after signing a contract with Gresini Honda.
Redding said: "I feel really knocked down at the moment. I came back from quite a big injury and I was again strong and then I got knocked down again and it had me thinking 'how many times do I have to get up?'
"I need to try and get the wrist ready to go because in MotoGP there is a lot more power, but I also want to go to the final race of the season in Valencia and be strong there because I want a good result.
"I have nothing to lose."
Despite Redding's fractured wrist, he was cleared to ride at Motegi and qualified 15th for Sunday's race.
Redding managed to avoid Alex Marinelarena's first-lap crash at the exit of Turn 2, but then ran into the bike of Esteve Rabat, who had also crashed.
That caused the race to be red flagged, with Redding, Rabat and Marinelarena taken to the medical centre.
The race was shortened to 15 laps and with Redding not taking part in the restart, Espargaro only needed to finish seventh to win the title.
But he snatched the lead from Kallio in the opening lap and went on to win the race with ease. Kallio finished second with Thomas Luthi third.
Earlier, Alex Marquez, the 17-year-old brother of MotoGP championship leader Marc, won the Moto3 race for his first grand prix victory.