With the morning passing by agonisingly slowly for the two title contenders, God's hand hovered above the Interlagos rain button.
In that choice quite possibly lay the outcome of the world championship, its final denouement after a season of see-sawing fortunes, of a sunny young guy who's already done it all but still thirsts for more, of the Spanish warrior who's cajoled his often-reluctant machine to join him in his quest of pulling off a coup.
They each waited, trying but failing to treat it as just any other race. A wet/anything-could-happen sort of afternoon would surely be Alonso's main chance, a straightforward/express-your-performance sort of day swerved things sharply into Vettel's territory, 13 points clear and three places ahead on the grid in a faster car.
In the garages engines would start up, run for a few minutes and be switched off, just keeping the oil warm, a normal routine but building the tension up another ratchet each time. The routines kept the Red Bull and Ferrari engineers one step removed but for the two contenders, just the wait - and the uncertainty of the weather.
Outside, the samba drums had started, the stadium was filling, the chanting had begun. The smell of roasting food filled the air. The driver parade came and went - Michael Schumacher up there for the last time chatting with Seb. "Michael was a god," he'd said earlier in the weekend, "a hero when I was a child, for me and the other kids in Kerpen. The first time I met him I didn't know what to say, because I didn't want to say something stupid." Now, talking to Michael was a welcome distraction - from that wait.
Yet it seemed in no time they were there, in the car, engine screaming, waiting for those gantry lights to go out down there in the gladiatorial coliseum that is just so appropriate a venue for the sport's final decider.
Still the weather hadn't decided what it was doing. Nothing more than a light mist of drizzle descended and everyone was on dries.
But one of the most incident-packed grands prix of all time was about to unfold, a race in which that crown swung with reckless abandon between the two contenders.
Vettel immediately lost ground at the start, while Alonso surged © XPB
The Alonso Phase (Laps 1-5)
It took only until the end of the first lap for Alonso to be in the exact position he needed (third, with Vettel outside the top nine) for the title, and ironically that situation had been partly triggered by Vettel's team mate - and Alonso's friend - Mark Webber.
Lewis Hamilton's McLaren was into an immediate lead from pole, chopping across and leaving Jenson Button to be zapped down the inside of the first corner by Felipe Massa.
Both Ferraris were fantastically quick off the line, Alonso immediately past Nico Hulkenberg's Force India and trying his patented outside Turn 1 move on the Red Bulls, Webber to his immediate left, Vettel pinned to the inside kerb.
"Mark squeezed me but I didn't want to be stubborn and fight and lose my front wing," was Vettel's post-race take. "So I had to back off and everyone went round my outside."
Not quite everyone, but certainly Webber, Alonso and Hulkenberg. As Hamilton surged down the back straight ahead of Massa and Button, Vettel concentrated on getting a slipstream up to Turn 4. The concertina effect of the closely-bunched cars as Vettel braked caused the following Lotus of Kimi Raikkonen to spear onto the run-off in avoidance.
The Senna shunt looked terminal for Vettel © LAT
As Seb then turned into the corner, Paul di Resta's Force India was initially the meat in a sandwich between Vettel and the Williams of Bruno Senna. Vettel chopped across di Resta but - perhaps unsighted by the Force India - did not appear to realise Senna was already partly into the corner. They hit.
"When you are in the midfield you need to be a bit more careful with how you take the corners," said Senna, who was out on the spot, the right-front suspension destroyed. "I was fully in control, absolutely everything was fine for me to take that corner there and he hit me very, very hard coming from the outside."
As Vettel spun backwards down the hill, 180-degrees to the traffic, with the crippled Williams alongside, Sergio Perez couldn't avoid the Red Bull and gave it a further knock into Senna. The Sauber was also out.
As for Vettel: "I just released the brakes and kept going backwards until they'd all passed. I was thinking, 'Just keep believing, stay calm.'"
Calm or not, he was plum last, with the left-hand rear bodywork seriously damaged around the exhaust area, but crucially he was still going.
These were horribly tense moments for those on the Red Bull pitwall. Had their title hopes just gone up in smoke? Was the car terminally damaged? Adrian Newey watched the data from the car intently.
The damaged Red Bull somehow held on © XPB
"We monitor the loads through the pushrods and could see that we had lost downforce, particularly at the rear," he explained.
"The other big concern was the crease that we could see in the exhaust system. Obviously if the exhaust breaks - which there has to be a high probability of with that sort of damage - it would probably catch the bodywork on fire at that point and your race would be over."
Vettel was instructed to change the engine mapping, giving a richer mixture to minimise the exhaust temperatures.
Button had crowded Massa on the way into corner four, compromising the Ferrari's line, making it slower down the hill and allowing the McLaren to get by on the inside as they exited five. It was a beautifully subtle bit of racecraft from Jenson who was now up to second.
As the screaming pack surged by, bobbing and weaving in a mad 200mph blur past the pits up to the Senna S, Webber was trying to take Massa's third place on the outside.
Alonso shoots down the inside of both Webber and Massa © XPB
Felipe held him out there as they approached the braking zone, leaving a lovely big gap to the inside for Alonso - who had been slipstreaming them for all he was worth - and Fernando was able to slip by them both. So, the beginning of lap two and Alonso was third, Vettel 20th and provisionally the crown was poised above the Ferrari talisman's Fonz-quiffed head by the margin of two points.
As Webber prevailed over Massa at the bottom of the esses, their squabbling allowed Hulkenberg to nail them both into the Descida do Lago, the Hulk's famed wet-weather driving skills combined with the Force India's liking of the cool track temperatures were proving a heady combination and Nico was showing no signs of stopping at fourth place, soon hassling Alonso's much-needed third and thereby threatening to put the crown back above Vettel's head.
Pastor Maldonado meanwhile had made it two trashed Williamses by crashing out of ninth at Turn 3 beginning lap two. Romain Grosjean lasted only another three laps before crashing the Lotus out heavily at Mergulho when trying to keep up with the charging Vettel.
Red Bull #1 was surging through the backmarkers. The car was a bit of an oversteering handful with all that body damage and the engine was not allowed to run in full power mode, but it was good enough for Seb to get a tune from, particularly as the surface became greasier. From 22nd and last at the end of lap one, he was on each subsequent lap 20th, 18th, 16th, 13th.
It was quickly evident that Fernando did not have the pace to take the race to the McLarens that were surging away in very close formation. Button several times got alongside Hamilton into Turn 4 and as the drizzle began to get a little heavier Jenson seemed to be more at ease with the slippery surface.
Alonso visited the Senna S run-off a couple of times © XPB
That surface caught out Alonso as he braked for the esses at the beginning of lap five. The inside front locked, running him slightly wide and taking the right-rear out of the dry groove and making it in turn lock up. As Fernando alternately steered and braked his way out of the crisis, he was forced to take the run-off - and Hulkenberg was through. Vettel was now provisionally ahead - by one point.
The Vettel Phase (Laps 5-71)
Although technically Vettel was always in the required position to take the title from this moment on, the capricious, unpredictable complexion of the race - and the ongoing concern about whether his damaged car would survive - did not allow that ever to feel secure.
As Alonso rejoined the track from his off at the esses he had to get seriously defensive out of Turn 3 as Webber sought to take advantage, with Massa in turn trying to repass Webber!
Alonso swerved into the pitlane exit lane to ensure he keep the inside line down to Turn 4. Fernando prevailed in that brief piece of brawling and a couple of laps later Massa would succeed in repassing Webber into Turn 1, giving Fernando his tailgunner. Soon after, Webber was hit by Kamui Kobayashi into a spin at the esses that lost him many places.
Button was clearly feeling held up by Hamilton in these conditions. He got ahead in the DRS zone on lap six but Hamilton repassed into the esses. It was only a matter of time though and Jenson went through properly two laps later in a move similar to that he'd put on Massa earlier, this time using the DRS facility to help compromise Lewis' line into Turn 4 and then nipping by him on the exit of Turn 4 as Hamilton twitched out of shape. Button quickly pulled away.
The drizzle was intensifying and at McLaren they were instructing their drivers to come in - but Button was adamant that he didn't yet want to. Hamilton - having just lost one second to Button on lap nine - was called in next time around. The stop was a little slow with a right-rear delay.
He was followed in by Alonso and Vettel. Was Red Bull now just tracking whatever Alonso did?
Red Bull's pitcrew was under huge pressure © LAT
"We had talked about that before the race," said Christian Horner, "but decided that we wouldn't do that but would just run our own race and not get distracted by whatever Ferrari might do."
Button was due in on the next lap, but during it came a realisation. "It's stopped raining, I'm staying out," he radioed.
Hulkenberg had made the precise same call and these two now had a big margin over the inters-shod pitters who were initially up to 3s faster - but only briefly until a dry line began to reform.
F1's two premier wet weather aces Button and Hulkenberg had used those skills to ride the very crest of an awkwardly-timed choice - and it had paid out to the tune of over 20s to the nearest of those who'd succumbed to the temptation to pit.
Massa had stayed out too, but his tyres were finished and after falling a long way back and being passed by the inters-shod Hamilton he was brought in on the 15th lap, this dropping him out of the immediate picture. Hamilton now lay third from Alonso, while Vettel was pressuring Kobayashi for fifth.
Upon rejoining from his pitstop Seb had been directly behind his team-mate and first-corner nemesis Webber. Acceding to a firm request from the team boss, Webber had been much more accommodating this time around, allowing Vettel an easy passage.
This left Vettel free to press home his attack on Kobayashi and on the 16th lap he went by him - under yellows! However, the move had been initiated before the flag came out. Race director Charlie Whiting had said at Austin that in such circumstances, and provided there was evidence that the driver had slowed, there would be no penalty, and so it was here.
Hulkenberg goes wheel to wheel with Button for the lead © XPB
Hulkenberg was absolutely revelling in these conditions and had quickly closed down the 3s gap to Button's lead. The pass came on the 19th lap going into the Senna S, the Force India slicing down the inside. Button fought back and for the next few laps kept the pressure on.
With the inters now seriously fading Hamilton and Alonso were in on lap 18 and fitted with respectively a set of primes and options. They were followed in by most of the inters-shod remainder the following lap. Those two extra stops over Button and Hulkenberg meant Hamilton, best of the rest, was now 45s back.
"There's a lot of debris out there," said Alonso on lap 20, in what could have been interpreted as a message to Charlie Whiting to get the safety car out - and thereby wipe out Alonso's big deficit to those ahead of him.
But just one lap later Nico Rosberg's Mercedes was trailing back to the pits with a rear tyre destroyed by debris. The safety car duly appeared - giving Hulkenberg and Button the opportunity of pitting for the first time, and having a fresh set of primes each fitted. But that safety car had wiped out their huge advantage.
The safety car erased Hulkenberg and Button's advantage © LAT
For the next seven laps Hulkenberg, Button, Hamilton, Alonso, Vettel, Kobayashi, the recovering Webber, di Resta and the rest circulated line astern. Upon the restart Hulkenberg timed his getaway perfectly. Kobayashi tried to get the jump on Vettel, with Webber making it three-abreast into Turn 1 but then taking to the run-off area, consigning himself to yet another comeback, while Kobayashi succeeded in moving Vettel down to sixth.
It soon became apparent that the damaged Red Bull was much more heavily compromised in the dry than in the wet.
"Yeah, in the wet I was able to keep a competitive pace by using different lines and things," said Seb. "But you cannot do that in the dry."
Button's front tyres were graining and on the second lap of the restart Hamilton was able to sweep past in the DRS zone and into Turn 4. But even Lewis could only slowly make an impression on Hulkenberg, as Button hung on still in touch.
The safety car had worked well for Massa and helped by an off for di Resta he was soon upon Vettel's tail. Seb made no attempt to hold Felipe behind, needing above all to get home. Massa then took Kobayashi around the outside of Turn 4 to place himself back as Alonso's tailgunner.
The next batch of rain was by this time threatening and the drizzle intensified. Leader Hulkenberg got a wheel on the wet white line into Pinheirinho and half-spun. In the time he took to collect it up, the flash of silver that was Hamilton was through.
Vettel was struggling at this point with serious tyre degradation. Complicating matters was a radio failure that meant the team couldn't hear him. He needed to come in for fresh tyres - but which to choose? Was that rain really coming? They decided it wasn't and went for dries. As he was leaving the pitlane the rain began falling heavier... Could this be about to get away from them?
Hulkenberg's slide wiped out Hamilton out © XPB
Meanwhile, his cause was about to be aided by Hulkenberg. On lap 54 he'd got a run going on Hamilton up the hill and down the pit straight but what happened next into the esses was complicated by the presence in front of them of the dicing Heikki Kovalainen and Timo Glock.
Hulkenberg on the inside line got his right rear onto the wet patch and with Hamilton right alongside, the rear slid suddenly into the McLaren, briefly flipping the Force India into the air and destroying Hamilton's front suspension. A sad but suitably dramatic note on which to end his McLaren career.
Button assumed the lead, Hulkenberg got going still second but would be forced to serve a drive-through for the incident, dropping him to fifth behind Alonso, Massa and the irrepressible Webber.
Vettel was struggling badly on his new slicks as the rain began to fall seriously now. He came in on lap 55 for a set of inters - but had no way of letting the team know he was about to do so. So the tyres weren't ready. It took an age before he was able to get going, and he was briefly down in 10th. But still on-course for the title.
The switch to inters went smoothly enough for Button, the Ferraris, Webber and Hulkenberg between laps 55-57. But less so for Kobayashi who spun on his in-lap and then found the wrong tyres waiting for him at the stop.
Schumacher said farewell from seventh © LAT
It all helped moved Vettel up to seventh. Michael Schumacher's tyre calls and wet weather skills made his final race a good one, passing Kimi Raikkonen and fending off a late Kobayashi challenge, with Kamui spinning down to ninth. Eight laps from home Michael chose not to resist when the former Schumacher-worshipping kid Vettel came past to go sixth.
Massa's stop a lap before Alonso's had put the wrong Ferrari temporarily ahead in second - something that Felipe corrected by dutifully backing off. It had been another great drive by Massa, looking now a lot like the driver of 2008.
For the remaining wet and misty distance, great calls were made of the drivers' car control skills - with both title contenders among those making phenomenal saves.
Two laps from the end leader Button almost lost control on the standing water at the top of the hill into the final turn. If that had happened Alonso would have won the race - and Vettel would have been fifth. Which would have made Alonso world champion. Instead, Button rescued the moment.
One lap later di Resta hit the same puddle - and went hard into the barriers. The final lap was held under the safety car. Two laps prior to that Vitaly Petrov had passed Charles Pic for what would be 11th place and thereby secured Caterham a place ahead of Marussia in the constructors' championship.
As Christian Horner shouted his congratulations to his triple champion over the radio he started to reel off the names he'd emulated: Fangio, Brabham, Stewart, Lauda, Piquet, Senna, Schumacher... "You forgot Prost," said the ever-alert and keen student of the sport's history. Horner of course couldn't hear him...