However, costly first-lap retirements in Belgium and Japan allowed his rivals to catch up, and defending World Champion Sebastian Vettel – like Alonso, a two-time title winner – took the lead in the sixteenth race of the season.
In the World Constructors' Championship, Red Bull Racing secured their third consecutive title when Sebastian Vettel finished second at the United States Grand Prix.
Six current or former World Drivers' Champions – Sebastian Vettel, Fernando Alonso, Jenson Button, Lewis Hamilton, Kimi Räikkönen, and Michael Schumacher – started the season, breaking the record of five established in 1970.
[62] Sutil was later the subject of criminal action, charged with grievous bodily harm after allegedly assaulting a senior Renault team member with a glass in a Shanghai nightclub following the 2011 Chinese Grand Prix.
[65] Scuderia Toro Rosso did not retain Jaime Alguersuari or Sébastien Buemi, instead choosing to replace them with Daniel Ricciardo and 2011 Formula Renault 3.5 Series runner-up Jean-Éric Vergne.
[154] Kimi Räikkönen finished seventh after a poor qualifying session saw him start the race seventeenth, taking advantage of a chaotic final lap to make up two places, while Felipe Massa and Bruno Senna both retired after a bizarre collision that saw their cars tangled up in one another.
[160] Fernando Alonso inherited the lead, with Sauber's Sergio Pérez a surprise second, having made an early stop for extreme wet weather tyres and then taking advantage of a rush to the pit lane to position himself in third at the restart.
[166] The FIA rejected the protest, and with Mercedes allowed to continue racing with their car unchanged,[167] Nico Rosberg took his – and the team's – first pole position since their return to Formula One in 2010,[168] while a penalty to Lewis Hamilton for a gearbox change promoted Michael Schumacher to second on the grid.
Daniel Ricciardo was involved in early contact that saw the Australian driver slide down the order from sixth at the start to fifteenth by the end of the race, having spent most of the Grand Prix caught behind Vitaly Petrov.
[206] Maldonado maintained a lead of seven seconds over Alonso, but a mistake by his crew during the third pit stop cost him time and left him vulnerable to the Ferrari driver in the final stint of the race.
Meanwhile, third-placed Kimi Räikkönen moved to an ambitious strategy that would see him attempt to force Maldonado and Alonso to race beyond the life expectancy of their tyres, allowing him to swoop in at the last minute to steal first place.
[208] Lewis Hamilton recovered from twenty-fourth on the grid to finish eighth, while Sebastian Vettel overcame a drive-through penalty and an unscheduled stop for a technical fault that forced his team to replace his front wing[209] to make a late move on Nico Rosberg for sixth place that would preserve his championship lead.
Horner ultimately chose the latter option, and Mark Webber started from pole,[213] establishing an early lead over Nico Rosberg as a first-corner accident eliminated four cars.
Red Bull Racing maintained their lead in the Constructors' Championship as rival teams chose not to follow through on the threat of their pre-race protest,[217] while Kovalainen finished thirteenth to see Caterham overtake Marussia for tenth place.
Starting eleventh,[236] he was forced to navigate his way through traffic, narrowly avoiding early contact between Bruno Senna and Kamui Kobayashi as Sebastian Vettel broke free of the field to establish a twenty-second lead by the first round of stops.
[239] Meanwhile, Michael Schumacher and Mark Webber had started to carve their way through the field by virtue of a late pit stop and easily picked off the minor points positions and taking advantage of the Maldonado—Hamilton collision to finish third and fourth behind Alonso and Räikkönen.
[255][256] As the championship moved into the second half of the season, Fernando Alonso maintained a thirty-four-point lead over his nearest rival, Mark Webber, with Sebastian Vettel a further ten points behind.
This was evidenced by Kimi Räikkönen, who inherited the lead after the first set of stops and produced a series of fast laps that allowed him to rejoin in second, coming dangerously close to team-mate Grosjean under brakes as he emerged from the pit lane.
[268] Maldonado retired shortly after the restart with a broken front wing after making contact with Timo Glock,[269] while Narain Karthikeyan spun off at Stavelot mid-way through the race when his wheel came loose.
The drivers had little opportunity to get comfortable on the restart, as Michael Schumacher misjudged his braking point at the end of the Esplanade Bridge, careening into the back of Jean-Éric Vergne and triggering the safety car for the second time in an accident that was a near mirror-image of his collision with Sergio Pérez in 2011.
Sergio Pérez added his name to the growing list of early retirements when he slid off at the hairpin under brakes and into the gravel trap whilst trying to force his way past a struggling Lewis Hamilton.
[307] Ferrari's strategy for staying in the championship battle saw them introduce upgrades to the F2012 at every remaining race in the season, starting with an extensive revision for the Indian Grand Prix,[308] but whatever advantage they offered was still not enough for Fernando Alonso to catch Sebastian Vettel.
[320] Vettel began to round up the HRTs, Marussias and Caterhams, but his early progress came at the expense of his front wing endplate when he made contact with Senna at Turn 8 switchback.
[321] During the safety car period, Vettel was forced to pit when he swerved to avoid Daniel Ricciardo and crashed into the polystyrene bollard marking the start of the DRS zone, further damaging his wing.
[326][327] Sebastian Vettel took his sixth pole position of the season, whilst Alonso struggled throughout qualifying to start the race ninth,[328] which became eighth when Romain Grosjean received a grid penalty for an unscheduled gearbox change.
Alonso recovered from seventh to finish third – marking the first time that he, Hamilton and Vettel had stood on the podium together in the one hundred races all three had contested together – and forcing the title fight to extend to the final round in Brazil.
[334] Further down the order, Massa overcame his gearbox penalty to finish fourth, while Jenson Button fell from twelfth on the grid to sixteenth at the end of the first lap, using an alternative strategy to claw his way back up to fifth.
Both Marussia drivers out-qualified the Caterhams for the first time, only for Timo Glock and Charles Pic be out-raced by Heikki Kovalainen and Vitaly Petrov, but the Russian team held onto tenth place in the World Constructors' Championship.
While Jenson Button and Lewis Hamilton fought over the race lead, Sebastian Vettel was involved in a first-lap clash with Bruno Senna that damaged his exhaust and spun him around, relegating him to last place.
[345] Three days after the Brazilian Grand Prix, reports began to surface suggesting that Sebastian Vettel's championship was under threat and that Ferrari would be filing a formal protest against the race results.