This is it - possibly. Ferrari's Fernando Alonso could land his third F1 title if he wins in Brazil and Red Bull's Mark Webber does not manage higher than fourth.
Webber looks pensive ahead of Friday's practice. He yet again suggested that Red Bull favoured his team-mate Sebastian Vettel. But it is the Australian not the German who is Alonso's nearest challenger.
McLaren's Lewis Hamilton is 21 points adrift of the leader, but stranger things have happened. Will fortune favour the former champion in the last two races?
Webber's team-mate Sebastian Vettel has the support of his mechanics as his car-seat underlines - but he is 25 points adrift of Spaniard Alonso.
Webber is out on the Interlagos track during the first practice with BBC 5 live's F1 analyst Anthony Davidson stating: "The Red Bulls look very stable."
Current champion Jenson Button's hopes of retaining his title hang by a thread. He is 42 points behind Alonso and needs a lot of luck. He finishes the first practice in fourth.
Vettel is fastest in first practice with team-mate Webber second and Hamilton third. The second practice should give a better idea as to how the teams will perform.
Alonso was 13th fastest. The Spaniard's engine died towards the end of the session but the Italian team had already planned for a replacement for second session.
However, Renault driver Vitaly Petrov was less fortunate when his car went off going into Turn Seven, while Sauber's Kamui Kobayashi also went off at the quick uphill right-hander known as Ferra Dura.
F1 supremo Bernie Ecclestone is joined former world champion Emerson Fittipaldi who twice won on his home circuit of Interlagos during the 1970s
Webber looks good again during the second practice session at Interlagos. The other Red Bull of Sebastian Vettel is also going well.
The Interlagos circuit runs past the favelas of Sao Paolo. Spectators and photographers try to get the best view of the action - possibly not from the safest spot.
Not many of the teams are showing their hand - here championship leader goes round the Interlagos circuit in second practice - he's in touch with the leading Red Bulls.
Mercedes driver Michael Schumacher's second practice almost ends in a crash - but the German manages to avoid a major collision with Toro Rosso's Jaime Alguersuari
No such luck for Felipe Massa who can only watch team-mate Fernando Alonso sweep past him after the Brazilian suffers a gearbox problem on his home circuit
A relatively uneventful session ends with Vettel again finishing fastest with team-mate Webber second. Ferrari's Alonso was third fastest with Hamiton fourth in his McLaren. Rain is expected during Saturday's qualifying - so expect a lot more thrills.