SAO PAULO, Brazil, Oct 21, 2007 (AFP) - Championship leader Lewis Hamilton was facing a titanic struggle to keep the wheels on his title bid after suffering a calamitous start to the Brazilian Grand Prix here on Sunday.

As pole sitter Felipe Massa in a Ferrari led at the halfway stage Hamilton, who had started alongside the Brazilian on the front row, was desperately trying to make up ground from ninth position.

The Briton, aiming to become the first rookie to win the title, was overtaken by his two title rivals Kimi Raikkonen and Fernando Alonso before the third corner, and then in his desperation to overtake his McLaren teammate Alonso he slithered off at the next bend.

Things went from bad to worse when he suffered engine problems on lap seven, plummeting down the field to 18th position.

By lap 35 he´d scythed his way through the pack to ninth.

Hamilton went into this title decider knowing that he needed to only finish second irrespective of where Alonso and Raikkonen finished to become the first rookie to claim the title and the first British victor since Damon Hill in 1996.

If Raikkonen wins Hamilton has to finish fifth or higher - if Alonso wins he has to finish second.

This is the first three-way showdown for the championship since 1986.

Success for Alonso would make him the first driver since the great Argentine Juan Manuel Fangio to win successive titles with different teams.