Despite making no fewer than six pitstops, Jenson Button secured his first win of the 2011 F1 season in a frankly astonishing Canadian Grand Prix after defending champion Sebastian Vettel threw away victory with a mistake on the final lap of the race.
Poor weather conditions led to a start behind the Safety Car, a stoppage of more than two hours and multiple caution periods before a dramatic dash to the flag that ended with Vettel buckling under Button's pressure just a handful of corners from the chequered flag.
Vettel had led the field away behind the Safety Car at the start of the race after persistent rain in Montreal and set about building a lead ahead of Ferrari pair Fernando Alonso and Felipe Massa when the field was released at the start of the fifth lap.
Behind, Mark Webber's hopes of victory took a hit when he was tipped into a spin by Lewis Hamilton into turn one and dropped down the order, while Hamilton lost position to both Nico Rosberg and Michael Schumacher having been delayed himself.
As Vettel set about trying to pull away at the front, Hamilton was trying to fight his way back up the order but lost a further place to team-mate Button on the sixth lap when Schumacher ran him wide at the hairpin as the McLaren tried to come round the outside.
The move would be the catalyst for the main talking point of the early stages as Hamilton then tried to reclaim position from Button when the 2009 title winner got slightly out of shape exiting the final corner, with Hamilton putting his nose alongside Button only for the pair to touch on the pit straight. While Button escaped, Hamilton made contact with the pit wall which damaged the left rear of his car and forced the Briton out – with the Safety Car deployed to clear the debris from the circuit and allow Hamilton's car to be retrieved after he ground to a halt at turn five.
Under the Safety Car, Button – who came on the radio to ask the McLaren team what his team-mate had been doing – pitted for intermediate tyres with Vettel leading the race from Alonso, Massa, Rosberg and Schumacher.
When the race resumed on lap 13, Vettel got a good enough restart to put distance between himself and the Ferrari's behind. However, all eyes were on Button to see how quickly he would now lap and, despite losing more places with a drive-through for speeding under the Safety Car, he was soon noticeably quicker than the cars ahead.
Alonso, Rosberg and Schumacher all pitted for intermediate tyres only for a torrential downpour to put the Safety Car back on track, with Vettel and Webber both pitting for a new set of wet tyres with what was basically a free stop. Those cars to have changed to intermediates were also forced back into the pits with Vettel running in the lead behind the Safety Car from Kamui Kobayashi, Felipe Massa, Nick Heidfeld, Vitaly Petrov and Paul di Resta – the order having been shuffled as some drivers elected to stay on track on their original wet tyres.
With conditions worsening, the red flag was thrown on lap 25 just after Vettel had radioed to his team that conditions were too bad to allow the race to continue.
The best part of two hours had passed before conditions improved enough to allow the race to restart, again behind the Safety Car. The action got back underway on lap 35 with Vettel keeping his lead and Kobayashi doing well to hold off Massa through the first corner.
With conditions improving, most of the field dived in for intermediates but it would be only three laps before the Safety Car was back on track after Alonso and Button clashed going into turn three, with the Ferrari ending up beached on the kerb on the outside of the circuit. Button meanwhile returned to the pits for another pitstop having suffered a punctured left rear.
Vettel was able to make his stop under the Safety Car and keep the lead ahead of Kobayashi, Massa, Heidfeld, di Resta and Webber – with Button now at the back of the field after his latest unscheduled stop.
On the restart, Vettel again made the most of the clear track ahead to break away from Kobayashi as he came under more pressure from Massa, while Heidfeld in turn was being pushed hard by di Resta before the Force India man tagged the Renault at the final corner and damaged his nose – being forced to pit for a replacement and then picking up a drive-through penalty for the incident.
As well as Button from the rear of the field, one man on a move was Michael Schumacher, who has battled ahead of Mark Webber at the hairpin to climb into the top six on lap 42 and then took fifth when di Resta was forced to make his unscheduled stop to replace his nose. Schumacher then got ahead of Heidfeld for fourth just before the race director deemed the circuit to be dry enough to allow DRS to be enabled on the 46th lap.
As drivers started to pit for dry tyres, Schumacher suddenly found himself in second place after Kobayashi ran wide and delayed Massa behind him and by the 54th laps, the leaders had all moved onto slick tyres with Vettel leading from Schumacher, Mark Webber, Kobayashi and Button – Massa having dropped out of contention after hitting the wall while lapping a Hispania just after exiting the pits and needing to take on a replacement nose.
Button soon got ahead of Kobayashi into fourth place but the Safety Car then reappeared after Heidfeld ran into the rear of Kobayashi out of turn two and lost the nose of his Renault on the circuit – leaving debris littering the track. While under caution, one marshal was lucky to escape being hit after falling with cars coming towards him on track as he attempted to remove parts of the Renault from the circuit. Heidfeld was out as a result of the incident having run over the wing and gone into the wall before sliding down the escape road at turn three.
The race resumed for the final time with just nine laps remaining, with Schumacher taking a look at Vettel on the restart before being forced to defend from Webber and Button behind. On lap 63, Webber made the most of the first DRS zone to get ahead of Schumacher into the final chicane but then cut the corner and was forced to concede the position back to the German on the following lap while also ensuring that Button couldn't follow him through.
On the following lap, Webber again ran wide at the final corner which allowed Button through into second place and on lap 65, the Briton used the DRS to get into second place going into the final chicane – setting the fastest lap in the process.
At that point, Button was 3.1 seconds behind Vettel but on the following lap, he brought the gap down to 1.6 seconds and on the penultimate lap, was close enough to be able to activate his DRS – meaning the pair started the final lap split by just 0.9 seconds. Before reaching the DRS zone for the final time however, Button was in the lead as Vettel made the smallest of mistakes and ran wide, allowing the McLaren through to take the most dramatic of victories.
Vettel crossed the line in second while Webber took third having finally managed to get ahead of Schumacher three laps from the finish. Schumacher's fourth place finish came after arguably his strongest race since coming out of retirement, while Vitaly Petrov took fifth for Renault.
A recovering Massa took sixth in a drag race to the line with Kobayashi's Sauber, with the Ferrari man getting close enough to use his DRS out of the final corner – taking the chequered flag just 0.045secs ahead of his Japanese rival.
Toro Rosso pair Jaime Alguersuari and Sebastien Buemi took eighth and tenth place, with the duo split by the Williams of Rubens Barrichello. Nico Rosberg could only manage eleventh, having appeared to lose pace after being nudged from behind by Adrian Sutil while running behind the Safety Car, while Pedro de la Rosa failed to score but was a solid twelfth on the lead lap after his late call up by Sauber.
Tonio Liuzzi was the best of the newcomers with team-mate Narain Karthikeyan just behind as Hispania beat both Virgin and Lotus on track.
To view the race result, CLICK HERE