There were a couple of moments during the 2013 Brazilian Grand Prix where it looked as though Sebastian Vettel's nine consecutive race win - his 13th in the season as a whole - might not actually materialise. They were only brief moments, and ultimately Vettel was comfortably in front when the chequered flag came out, but they were there nonetheless, indicating a slightly scrappier and more hard-fought victory than the recent easy sweeps he's enjoyed in an utterly dominant second half to the world championship season.
As the lights went out, it was a leap into the unknown for everyone in the grid as they got their first taste of the weekend of a dry track at Interlagos. Pole man Vettel clearly feared a blitz attack from the Ferrari of Fernando Alonso off the second row and moved over to defend accordingly. In fact the danger came from Nico Rosberg who was starting alongside Vettel on the front row; Vettel realised too late that he had lost the lead to the Rosberg going into turn 1, while Lewis Hamilton proved it was no isolated success for Mercedes as he also managed to take advantage of the scrap at the front to pass both Alonso and Mark Webber and run in third place through the first lap.
But that early advantage came with a cost, the two Mercedes cars clearly running more rear wing than their rivals which left them vulnerable to attack through the long sweeping slingshot at the end of the lap. Having been dancing all over the rear of Rosberg's car, Vettel was able to blast his way past Rosberg to reclaim the lead as the two cars passed the start/finish line for the first time, while Hamilton similarly fell foul to first Alonso and then to Webber who was able to pull around the outside of turn 6 to return Hamilton to fifth place ahead of Felipe Massa and Nico Hulkenberg.
Alonso wasted no time and was soon dismissing Rosberg for second spot on lap 4, but by this stage Vettel had already pulled out a six second lead which was increasing at a rate of a second per lap, meaning that the world champion was looking well on course for his ninth consecutive Grand Prix race victory of the season. Unable to rein in the Red Bull at the front, Alonso inevitably came under pressure from the one immediately behind that was being driven by Webber: a dadb of DRS finally delivered the inevitable result on lap 13.
Virtually everyone had started on the medium option tyres - Jean-Eric Vergne becoming the first man to pit in the race on lap 11 - but it was the two exceptions to the rule who were delivering standout performances further back. By lap 15, the harder prime tyres had seen Jenson Button climb up from 14th on the grid to run in seventh place and Esteban Gutierrez also gaining four places to run in 13th. The Mercedes pair by contrast were struggling on their first set of options, but teams were urging their drivers to grin and bear it a while longer because of the forecast of incoming rain which would yet prove to be a gamechanger that would force everyone into the pit lane for intermediates at short notice and obviate the need for the cars to run on both sets of slick compounds.
Drivers started to reach their limit before any of the hotly anticipated rain could show up, with Daniel Ricciardo, Adrian Sutil and Valtteri Bottas all cycling through, along with Heikki Kovalainen who came in on lap 16 and who was now the sole remaining Lotus in the race after an oil leak on Romain Grosjean's car saw the Frenchman exit the race in a thick plume of smoke on just the second lap of the race.
Felipe Massa and Sergio Perez were in on lap 20, Jenson Button and Nico Hulkenberg in next time around, and Alonso and Hamilton following suit on lap 22 despite spots of rain being discernible in the air, the teams now growing more convinced that this early weather front would yield only a light and brief shower after all. Rosberg's stop on lap 23 saw him emerge behind Jenson Button's McLaren that was now in sixth place, while a delay on the left rear during Webber's stop on lap 24 saw the Australian come back out just behind Alonso - although it only took Webber a couple of laps to smartly move back ahead of the Ferrari to restore his claim to second place.
Vettel's own pit stop on lap 24 was problem free, and by lap 26 he was a full ten seconds clear of the competition with Webber, Alonso, Massa, Hamilton and Button rounding out the top six and Rosberg in seventh leading a train of cars consisting of Perez, Hulkenberg and Ricciardo. The threat of an immediate rain shower had evaporated into thin air, but there were dark storm clouds over the head of Felipe Massa in his last race in the Ferrari, as he was hit by a drive-thru penalty for cutting the white line at pit entry - a possibly crucial moment in the constructors championship battle for second place between Ferrari and Mercedes. Massa dropped to eighth place behind Perez as a result of the "unbelievable, unacceptable" penalty, which he objected to with some eloquent hand gesturing as he served the punishment.