There were some classic battles shaping up through the field, Rosberg having to work hard to keep third place out of Mark Webber's hands while further back Adrian Sutil and Felipe Massa were having something of an epic battle over ninth place. All the time, though Vettel was disappearing further and further into the distance, a 17-second leap by the time the 30-lap marker was reached.
A DRS boost on the run to the final chicane on lap 31 finally allowed Webber past Rosberg for the final podium spot and the Australian immediately set a fastest lap in the clear air. The overtake also broke Rosberg's momentum to the extent that Alonso quickly sneaked past seconds later; Rosberg responded by pitting for the second time today for a fresh tyres next time by, the Mercedes clearly still struggling to make the Pirelli tyres last as long as they need in race conditions since Rosberg was now told he'd have to make it to the end of the race - another 39 laps! - on the newly-installed set of tyres.
As the race hit half distance, Vettel's lead over Hamilton was still massive, while Hamilton himself still had nine seconds in hand over Webber who had damaged his front wing in a collision with lapped backmarker Giedo van der Garde in the Caterham at the hairpin which earned the Dutchman a 10-second stop-go penalty from the race stewards. The top three were followed by Alonso, Rosberg, Vergne, Paul di Resta and Romain Grosjean (both still to pit for the first time having opted to start on the medium compound tyres) followed by Sutil and Massa whose early charge had fizzled out.
Initially it seemed that the wing damage to Webber's car wasn't too much of an issue, as he and Alonso continued to reel in Hamilton up ahead; but eventually on lap 42 the Ferrari pounced and flew past the hobbled Red Bull to wrest the final podium position away with surprising ease. Even so, the team opted not to change the front wing on Webber's car when he came in for his second and hopefully last pit stop.
Webber's old sparring partner van der Garde had front wing problems of his own after contacting the back of Nico Hulkenberg's Sauber on lap 48, and the two cars ended up pulling over and retiring shortly afterwards - the first cars out of the Canadian Grand Prix. Although a safety car was never in prospect, Lewis Hamilton took the advantage of the waved yellows out on track to dive into pit lane for his final stop, which prompted the race leader to do likewise next time by.
A rare mishap from Vettel on lap 52 saw him cut over the grass and lose four seconds from his lead, but he still had a comfortable 15 seconds in hand while Lewis Hamilton was far more concerned with the rapidly closing Fernando Alonso behind him, now flirting with getting into DRS range at which point it was surely game over for the Mercedes in terms of retaining second spot. At least his day was going better that that of his team mate, as Rosberg was forced to come in for a new set of tyres after locking-up and flat-spotting the previous set on lap 58.
One man not having trouble with tyre wear was Paul di Resta. Having gambled on a contrary strategy by starting on the medium compounds, the Force India had managed a mighty 57 laps before coming onto pit lane for replacements, which would have to be a set of supersofts in order to adhere to regulations. By contract the only other top driver to try the strategy, Lotus' Romain Grosjean, had been forced to pit on lap 43 leaving him much more to do on the short-lived options.
The inevitable battle for second place was momentarily delayed by the presence of Adrian Sutil just ahead which gave Hamilton a DRS activation with which to fend off Alonso. Once the pair were past the Force India - Sutil getting a drive-thru for ignoring blue flags in the process - it was finally Alonso's time to bring all his guns to bear on the Mercedes, and while Hamilton initially warded off the attack by parking his car on the apex of the hairpin on lap 61 it was just a matter of minutes before Alonso finally pounded and passed the Briton on the outside line into turn 1. There was contact, and some flying pieces of bodywork, but nothing serious enough to significantly affect either car.
Of course, this swung the advantage of the DRS activation to Hamilton's corner and now it was Alonso's turn to defend and it wasn't until he edged his way out of the one second gap on lap 65 that he could finally be sure that Hamilton wasn't about to counterattack. Hamilton would have to settle for third place, and that seemed relatively secure as Webber was still troubled by compromised aerodynamics as a result of his broken front wing.
With Vettel, Alonso and Hamilton clinching the podium and Webber and Rosberg the only other cars left on the lead lap by the finish, the remainder of the top ten was filled out by lapped cars - Vergne, a valiant di Resta, Massa, Raikkonen and Sutil. There was also a final retirement from the race when Esteban Gutierrez put his Sauber into the tyre barrier after exiting pit lane on a new set of tyres, but the threat of a finish to the race behind the safety car was averted by quick action by the track marshalls retrieving the stricken car under local double waved yellows instead.