Lewis Hamilton put in a Mclaren masterclass to catch and overhaul two World Champs on the way to his third Canadian GP victory.
In a race that was determined more by strategy than on-track action, Sebastian Vettel lead from the start before dropping to third behind both Hamilton and Alonso after the first round of pit-stops.
However the decisive phase was from Lap 50 to the flag at Lap 70 when Hamilton came in for a second pit-stop while both Ferrari and Red Bull opted to stay out and try and make their tyres last till the end of the race. It cost them both podiums as Romain Grosjean and Sergio Perez sped past them in the closing stages with a late stop from Vettel salvaging fourth place and Alonso hanging onto fifth.
It was another dismal race for Jenson Button who simply couldn't get his car to work and Felipe Massa who spun down the order from 5th to 12th early on.
Summer had definitely arrived in Quebec with the sun beating down on the Isle Notre Dame circuit with an ambient temperature of 27C making the track a Bahrain-like 45C
Six Rows of Grid
1.Vettel, 2.Hamilton, 3.Alonso, 4.Webber, 5.Rosberg, 6.Massa, 7.Grosjean, 8.DiResta, 9.Schumacher, 10.Button, 11.Kobayashi, 12.Raikkonen.
Considering there have been some chaotic starts at the start in Montreal in the past, when the red lights went out it was a very orderly queue through Turns 1 and 2 with no dramatic moves forward or backward and no carbon fibre strewn across the track.
Paul Di Resta managed to make a place on the Lotus of Romain Grosjean, the French driver wanting more than any other to have a clean getaway having had incidents at the start of the last two grands prix. Mark Webber came under pressure from Nico Rosberg for P4 and they ran side by side with a bit of wheel touching, but both came through it unscathed with the Red Bull car maintaining its position.
Sebastian Vettel held the lead comfortably and set off to establish an early gap and finished the opening tour 1.1 seconds ahead.
Position at the end of Lap 1: 1.Vettel, 2.Hamilton, 3.Alonson, 4.Webber, 5.Rosberg, 6.Massa, 7.DiResta, 8.Grosjean, 9.Schumacher, 10.Button, 11.Raikkonen, 12.Kobayashi, 13.Perez
By the end of the opening lap Felipe Massa was already putting pressure on Nico Rosberg for P5 with the Mercedes driving defensively. He followed closely on Lap 2 and by the time DRS was enabled on Lap 3 was able to make an easy pass on the back straight.
Jenson Button had started the race on the Soft tyre, unlike the front-runners who were on the SuperSofts. He now came under pressure from Kimi Raikkonen who had elected to use Softs and was using them better. However it would still take him till Lap 15 to get past the struggling Brit despite getting into the DRS zone.
Paul DiResta took a place off Nico Rosberg on Lap 3 pushing him down to P7. Up at the front Vettel was having trouble building a substantial lead. By Lap 4 it was 1.9 and a lap later it was only 1.8 as he and Lewis Hamilton traded fastest laps. Fernando Alonso in P3 wasn't letting them get away but they were edging a small gap to Mark Webber.
Felipe Massa's race took a disastrous turn at the beginning of Lap 6 when he spun his Ferrari F2012 across the grass at Turn 1 and fell from P5 to P12, taking some life out of the tyres as he did so. In the opening phase of the race it looked like most drivers (apart from Massa) wanted to see how "the deg" tyre degradation was working out and not push too hard.
The gap between Vettel and Hamilton on Lap 10 was just 1.5 seconds, with Alonso 1.3 behind Hamilton and Webber a further four seconds back. It was on this lap that all of the top 16 cars recorded a 1:20s lap of some description.
Michael Schumacher and Paul DiResta were the first drivers in the top ten to pit for tyres, on Lap 14, while sensing that the action might be about to kick off at the front, Hamilton set two fastest sectors and Alonso put in a Personal Best time to close the gaps to 1.2 and 1.7 respectively. On Lap 15 Vettel's lead was down to just 0.7 seconds and at the end of Lap 16 he pitted for a set of Softs his tyres fading fast. Hamilton came in a lap later and managed to jump the World Champion in the process, however Fernando Alonso sprinted for another two laps and managed to exit in front of them both at the start of Lap 20.
Unfortunately for Fernando, Hamilton's tyres were switched on and Lewis was right on his exhaust going through the DRS detection zone. Alonso tried to resist going down the long back straight but Hamilton was through into the lead with Vettel lurking just behind
Positions on Lap 20
1.Grosjean (not stopped), 2.Hamilton, 3.Alonso, 4.Vettel, 5.Raikkonen (not stopped), 6.Kobayashi (not stopped), 7.Perez (not stopped), 8.Hulkenberg (not stopped), 9.Webber, 10. Rosberg, 11.Maldonado (not stopped), 12.Massa.
Button, despite running the supposedly more durable Soft tyre had already pitted on Lap 15 and was doing no better on SuperSofts, his race having turned into a 70-lap set-up test.Grosjean pitted from the lead on Lap 21 and Hamilton set out to open a gap to Alonso behind him with fastest laps on Lap 22 and 23 and then again on Lap 26 and 27. By this stage the lead over Alonso was up to 3.1 seconds. Alonso wouldn't be shaken off and was putting in Personal Best times in response, with Vettel less than two seconds further back.
Both Kimi Raikkonen and Sergio Perez had yet to stop and whereas the Sauber of Kamui Kobayashi had gone in for tyres on Lap 24, Perez was making his Softs last - even better, he was closing in on Raikkonen in front. Both were almost matching the laptimes of the leading three cars.
Positions on Lap 30
1.Hamilton, 2.Alonso, 3.Vettel, 4.Raikkonen (not stopped), 5.Perez (not stopped), 6.Webber, 7. Rosberg, 8.Grosjean, 9.Massa, 10.DiResta, 11.Kobayashi 12.Schumacher
Hamilton edged out the gap to Alonso to 4 seconds by Lap 35 and while Nico Rosberg dived down pitlane for his third set of tyres at the end of Lap 39, Kimi Raikkonen had set a Personal Best on his original set on Lap 38! He finally pitted on Lap 40 and exited in P8.
Raikkonen came out in front of Rosberg who used his warmed up tyres and the DRS (as Hamilton had done with Alonso) to take back P8. Sergio Perez finally made his single stop for Sauber a lap later and came out just in front of the Rosberg and Raikkonen battle. Rosberg held his line round the inside of Turn 2 as the pitlane fed Perez back in and the Mexican had to settle in behind Rosberg.
While this was happening, Mark Webber got his braking all wrong into Turn 3/4 skipping across the grass and allowing Romain Grosjean to close up and put the Red Bull under pressure.
Positions on Lap 44
1.Hamilton, 2.Alonso, 3.Vettel, 4.Webber, 5.Grosjean, 6.Massa, 7.Rosberg, 8.Perez, 9.Raikkonen 10.Kobayashi, 11.DiResta. 12.Ricciardo
Michael Schumacher had had more than his fair share of technical problems in 2012 and on Lap 45 it became evident that his DRS had jammed open. He was already out of the points but had no other choice than to retire the car for another DNF.
There were a lot of marbles developing off the racing line now making overtaking more hazardous and with relative stasis at the front eyes turned to Sergio Perez who was catching Nico Rosberg (himself no slouch putting in fastest laps on Lap 40 and 49).
Leader Lewis Hamilton radioed back that his tyres were beginning to go on Lap 47 and his lead over Alonso came down to 2.6 seconds on Lap 49. At the end of Lap 50 Lewis was in for his second stop of the afternoon and rejoined in third place. The McLaren pitcrew work again looked less than 100% despite their new swivel jack and Lewis almost got caught out by the anti-stall kicking in again. Surely now Alonso and Vettel would sprint using the remaining life in their tyres and try and get in front...?
Lewis's first lap out of the pits was only a 1:20 and he looked vulnerable as Alonso and Vettel put in 1:18s. But then on Lap 52 he put in a Fastest Lap 1:17.244, followed by a 1:17.135 and Alonso didn't have enough time to get in and out of the pits and stay in front. His only hope now was hanging on in front.
Positions on Lap 54
1.Alonso, 2.Vettel, 3.Hamilton (two stops), 4.Grosjean, 5.Massa, 6.Rosberg (two stops), 7.Perez, 8.Webber (two stops), 9.Raikkonen 10.Kobayashi
Hamilton was now going consistently over a second a lap quicker than the two cars in front and with 15 laps to the flag and a compliant DRS the win looked on. What also looked apparent was that Grosjean could match Hamilton's pace and if either Vettel or Alonso stopped now, they would drop behind the Lotus driver.
Sergio Perez was fast, too - and whereas the one-stopping Raikkonen had come up against an impassable Mark Webber which halted his progress, Perez was right up behind Rosberg who was pressuring Massa. On Lap 57 Rosberg failed to make an overtaking move on Massa stick, cut the final chicane and had to hand the place back. The complication was that Sergio was right behind and so he handed over two places.
A lap later and Perez was past Massa, then Rosberg and when he came under pressure from Mark Webber at the Casino hairpin decided he had to come in for tyres. It saved his tenth place.
Hamilton continued his inexorable pursuit of Vettel and Alonso. By Lap 60 Alonso was just 4.3 seconds in front of the third place man. Lewis cruised past Vettel on Lap 62. At this stage Vettel and Alonso were doing 1:19s while behind them everyone from P4 to P12 was doing 1:17s.
Vettel saw the writing on the wall and pitted straight afterwards. Alonso continued. Hamilton overtook him on Lap 64, Grosjean passed him on Lap 66. By Lap 67 Fernando was losing 1.3 seconds per sector and the pursuing Vettel in 5th place was four seconds a lap quicker. In fact Vettel produced sparks from his front right wheel after contact with the Champions Wall. He still set the Fastest Lap despite it.
Perez passed the ailing Ferrari driver on Lap 68 and Vettel caught him at the Casino Hairpin on Lap 69 of 70. Another lap and the closing Rosberg, Webber and Raikkonen would have relegated him even further.
As it was Lewis Hamilton crossed the line to become the seventh winner in seven races and take the lead in the drivers' title race. Romain Grosjean came home just 2.5 seconds back in P2 with Perez clinching P3 from fifteenth on the grid. Vettel claimed Fastest Lap of the race in P4 with Alonso clinging onto P5, Rosberg P6, Webber P7, Raikkonen P8, Kobayashi P9 and Massa in P10.
It had been another Canadian GP of late-race drama and a reversal of fortunes for the McLaren drivers from 2011. With Lotus and Sauber performing well in the heat, there's no reason why it can't be eight winners from eight races in Valencia.
01. Hamilton McLaren-Mercedes 1h32:29.586
02. Grosjean Lotus-Renault + 2.513
03. Perez Sauber-Ferrari + 5.260
04. Vettel Red Bull-Renault + 7.295
05. Alonso Ferrari + 13.411
06. Rosberg Mercedes + 13.842
07. Webber Red Bull-Renault + 15.085
08. Raikkonen Lotus-Renault + 15.567
09. Kobayashi Sauber-Ferrari + 24.432
10. Massa Ferrari + 25.272
11. Di Resta Force India-Mercedes + 37.693
12. Hulkenberg Force India-Mercedes + 46.236
13. Maldonado Williams-Renault + 47.052
14. Ricciardo Toro Rosso-Ferrari + 1:04.475
15. Vergne Toro Rosso-Ferrari + 1 lap
16. Button McLaren-Mercedes + 1 lap
17. Senna Williams-Renault + 1 lap
18. Kovalainen Caterham-Renault + 1 lap
19. Petrov Caterham-Renault + 1 lap
20. Pic Marussia-Cosworth + 2 laps
Did not Finish
Glock Marussia-Cosworth 57
Schumacher Mercedes 34
De la Rosa HRT-Cosworth 25
Karthikeyan HRT-Cosworth 23