Just four corners into the race, it looked as though the German had gifted the title to the tenacious Fernando Alonso. The young champion fought back however, braving a series of incidents and unpredictable weather.
Lewis Hamilton and Nico Hulkenberg both lost out on fairytale finishes as they departed their respective teams and Mark Webber had an eventful end to a disappointing season, finishing fourth. Daniel Ricciardo finished thirteenth.
Practice and Qualifying
Qualifying started on a wet track, but by the end of Q3, it was sunny. McLaren read the conditions best, with Hamilton and Button taking the British team's 62nd front-row lockout.
Webber took third and his championship-leading teammate lined up beside him.
Alonso was again outqaulified by teammate Massa but both were promoted a place after Pastor Maldonado was belted with a ten-place grid penalty for missing the weighbridge.
The grid lined up under the lightest of drizzles, with all cars on slicks. Interlagos is famous for first corner shenanigans, making for an unusually tense start.
Hamilton launched off the line, but the Ferraris rocketed from three rows back, Massa getting in front of both Red Bulls, with Alonso close behind.
Webber appeared to shield Vettel from any miscreant behaviour, but they were both engulfed.
The first corner was otherwise uneventful - but then it went horrifically wrong for Vettel at turn four.
The first sign of trouble was Kimi Raikkonen locking up and almost leaping off the track in a cloud of tyre smoke to avoid collecting Vettel.
Bruno Senna made it up the inside of the Red Bull, but Vettel turned in to the Williams and threw himself into a spin, Senna collecting him for a second time.
Vettel waited for the entire field to pass him by before spinning around and setting off to try and repair the damage to his race, his team telling him to stay out.
Another victim of the fracas was Sergio Perez in his last race for Sauber.
The damage to the RB8 was on the trailing edge of the floor, ahead of the left rear wheel, with regular images of Adrian Newey staring at a photograph of the cracked carbon fibre.
Nico Hulkenberg took third in the mess during the first lap, streaking past the Ferraris and the Red Bull of Mark Webber.
Webber battled the Ferraris of Felipe Massa and Fernando Alonso, with Massa blocking heavily to protect his team leader.
Alonso shot past both of them and a lap later out-braked himself and ended up on the green concrete at turn one, almost losing the place.
By the eighth lap, Vettel had worked his way back to eighth place as Romain Grosjean threw the Lotus into the wall at turn four, the track becoming slippery as the rain began to fall.
Massa's mobile chicane act brought Kamui Kobayashi right up on to Webber's gearbox and it wasn't long before the Sauber driver pitched Webber into a spin, neutralising his threat to the Ferrari team. Kobayashi's front wing needed replacing and he pitted.
Up front, the McLaren team battled between them with Button trying repeatedly to spoil Hamilton's bid for victory in his McLaren swansong. Button got past and edged out a lead.
Hamilton pitted for intermediates on lap 11 after Webber had done the same on lap 10. Alonso followed Hamilton in, as did Vettel, dropping him to sixteenth and back with Webber, who duly let him through after rejoining.
Button and Hulkenberg stayed on slicks, putting the two of them way out in front in the changing conditions. The German, in his last race for Force India, had caught the McLaren of Button and battled the Briton for first.
After just a few laps, Hamilton radioed his team to tell them the intermediate tyres were going off, it just wasn't raining quite enough to keep them cool. Massa was struggling to keep cars behind him on the slick tyres.
Hulkenberg took the lead on lap 19 after Button got a little out of shape into the final turn, the Force India breezing around the outside and into the Senna esses in front.
Hamilton pitted on lap 19, as did Alonso, both of them returning to slick tyres.
Nico Rosberg's miserable second half of the year continued, the Mercedes' right rear puncturing courtesy of debris and forcing him to tour around the lap for a replacement.
This brought out the safety car to clear the track surface. Button and Hulkenberg pitted, with the Force India staying in front of the McLaren at the pit exit.
Behind the safety car, Vettel ran fourth and Alonso fifth, the championship slipping away from Alonso despite the calamity that had befallen Vettel. Neither of the accidents involving the Red Bulls were to be investigated, the stewards uncharacteristically quiet.
The safety car period seemed to go on forever and the SLS didn't return to the pits until the end of lap 29. Hulkenberg bunched the pack up behind him and then launched himself on to the main straight with a handy gap.
Kobayashi, Vettel and Webber went three abreast after Vettel was too slow on the restart. The Australia was hung out to dry on the outside, forcing him off at turn one and dropping him to thirteenth which rapidly improved.
Hamilton took second from Button and set off after Hulkenberg as the skies once again darkened slightly. Kobayashi surprised Fernando Alonso by passing him on the back straight, putting the two championship contenders together.
Alonso came back at the Sauber at the end of the next lap while Massa steamed past di Resta to get himself behind Vettel. Massa put himself on the outside of the Red Bull on lap 34 and passed at turn four to push Vettel back anther place.
Alonso needed Vettel to lose another five places for the championship, however and had to bank on the German's damaged car to let him down.
Massa shouldered his way past Kobayashi on lap 37, leaving the Sauber for Vettel to deal with. Webber worked his way back in to the points, finding himself eighth by lap 41.
Tragically for Force India, Hulkenberg just dropped a rear tyre on to the white line on lap 48, throwing the car sideways and opening the door for Hamilton to drive back into the lead. Hulkenberg was part of a long line of drivers who had done that over the previous six laps.
On lap 53, Vettel pulled in for medium compound tyres, the first to blink as the field's tyres began to look second hand, the drivers unable to get enough heat into their rubber.
Hulkenberg fought back on lap 55 as Lewis Hamilton was held up by Timo Glock. Hulkenberg was past but just got it out of shape into the left-hander, the car sliding into Lewis Hamilton's front left. The Force India took to the air and nearly into a roll, but the damage was done, Hamilton's car was crippled and he trudged back to the pits.
To add insult to injury, Hulkenberg was given a drive-through penalty for what was a genuine racing incident.
Vettel pitted again on lap 55 but it was a minor disaster as there were no tyres available for him, the team eventually bolting on a set of intermediates. He was followed in a lap later by Alonso and Button.
Button held a huge sixteen second lead over Massa by lap 60 as the Brazilian backed off to allow Alonso through into second place, the McLaren driver stretching his overall lead to 22 seconds.
Vettel caught Michael Schumacher despite his team's assurances his seventh position was good enough, taking sixth from the retiring master on lap 64.
As important as the title battle was, Caterham and Marussia were locked in mortal combat for tenth place in the constructor's championship and $25 million of TV money for 2013. Petrov passed Pic for twelfth as the Frenchman got out of the way of a passing Ferrari.
The most incredible championship in over 15 years ended behind the safety car as Paul di Resta slammed into the wall coming up the hill onto the main straight on lap 70, an echo of Mark Webber's crash there almost a decade ago in the Jaguar.
This handed the championship to Sebastien Vettel and the vanquished Alonso stood tall in second place on the podium, his dutiful teammate third at his home race.
"It's difficult to imagine what goes through my head now, I am so full of adrenalin. It was an incredible race, everything that could have happened to make it more difficult for us today, happened," Vettel said after the race, admitting the third championship was yet to sink in.
Michael Schumacher finished his career in seventh place, the smiling German veteran exiting the stage as he had entered it over two decades ago.
2012 Brazil F1 GP Results
- Button - McLaren-Mercedes
- Alonso - Ferrari
- Massa - Ferrari
- Webber - Red Bull-Renault
- Hulkenberg - Force India-Mercedes
- Vettel - Red Bull-Renault
- Schumacher - Mercedes
- Vergne - Toro Rosso-Ferrari
- Kobayashi - Sauber-Ferrari
- Raikkonen - Lotus-Renault
- Petrov - Caterham-Renault
- Pic - Marussia-Cosworth
- Ricciardo - Toro Rosso-Ferrari
- Kovalainen - Caterham-Renault
- Rosberg - Mercedes
- Glock - Marussia-Cosworth
- De la Rosa - HRT-Cosworth
- Karthikeyan - HRT-Cosworth
- Di Resta - Force India-Mercedes
- Hamilton - McLaren-Mercedes
- Grosjean - Lotus-Renault
- Maldonado - Williams-Renault
- Senna - Williams-Renault
- Perez - Sauber-Ferrari