It was the seventh race of the 2014 Formula One World Championship and the 45th time the Canadian Grand Prix formed part of the series.
The race was neutralised with the safety car on the same lap due to a crash between Marussia teammates Max Chilton and Jules Bianchi.
Competitive racing ended with the safety car's deployment on the final lap due to a first turn accident between Massa and Pérez that saw both drivers briefly hospitalised.
The result increased Rosberg's lead in the Drivers' Championship to 22 points over his teammate Hamilton who retired with overheating rear brakes.
Renault (Red Bull's power-plant supplier) and Ferrari would have to have done an exceptional job coming into this weekend, in terms of that area, to be able to keep up with us on the straights.
[14][15] GP2 Series participant and Caterham reserve driver Alexander Rossi drove the CT05 in lieu of Kamui Kobayashi for the first time in 2014.
[17] Toro Rosso built new exhaust systems for their two cars following the development of fractures from possible overheating that led to their retirements in Monaco.
The Red Bull duo of Sebastian Vettel and Ricciardo were fourth and sixth; they were separated by Valtteri Bottas for Williams.
[28] The session was red flagged 15 minutes in when Esteban Gutiérrez had a loss of control at the rear of his Sauber's braking through the turn three and four chicane.
[27][29] Sauber discovered its front was too heavily damaged; Gutiérrez would miss qualifying because the team's spare chassis had to be constructed for the race on Sunday.
[35] The stewards gave Maldonado his first reprimand of the season because he did not refit his steering wheel after vacating his car as required by the Formula One regulations at the exit of turn three.
[31] He was required to begin from the pit lane because Sauber changed the gearbox and the chassis of his car as a result of his third practice accident.
The accident prompted the safety car's deployment since track marshals were needed to clear oil and debris laid on the circuit.
[47] On the next lap, a turbocharger connector pipe failure on Ericsson's car prompted his retirement in the pit lane to prevent engine damage.
[46][48] Rosberg clipped a kerb on the inside of turn four and lost control at the rear on that lap; he narrowly avoided contact with a barrier and continued.
[52][53] As Hamilton slipstreamed Rosberg on the main straight that lap,[50] his teammate locked his tyres into the final chicane and cut the corner.
[47][50] Hamilton had drawn close to his teammate Rosberg; Mercedes observed warm temperatures on both cars' engine control systems on the kinetic motor–generator units.
[2][50] That lowered their top speed on the straight by 32 km/h (20 mph) and were four seconds a lap slower than before after instructions to restart the electric control systems were unsuccessful.
[50][54] Hülkenberg made his pit stop on lap 41 and Williams put the third-placed Massa on a one-stop strategy due to Mercedes' reduced pace.
[50][52] Hamilton then slipstreamed back past with DRS; he ran onto a run-off area at the final corner,[50] and passed Rosberg, before relinquishing second position to his teammate.
[46] Pérez rammed into a barrier at 32G,[55] as Massa narrowly avoided collecting Vettel en route into a tyre wall in a 27G impact.
[56] The safety car was deployed to neutralise the race and Ricciardo took his first career victory, the first for an Australian since Mark Webber won the 2012 British Grand Prix.
Off the podium, Button, Hülkenberg, Alonso, Bottas, Vergne, Magnussen, Räikkönen, Pérez, Massa, Sutil and Gutiérrez were the final finishers.
[47] At the podium interviews,[57] conducted by the 1995 winner of the race Jean Alesi,[58] Ricciardo said he was in shock over his first career win, "This is ridiculous!
[57] In the subsequent press conference, Ricciardo said he believed that more confidence and familiarity with the Formula One community helped him to win the Grand Prix.
"[57] Vettel said he felt Red Bull had been fortunate after several issues early in the season and finishing the race ahead one of the Mercedes, "I think that's a very, very positive day for us.
They were later airlifted to the Sacre Coeur hospital for a pre-cautionary check-up because their crashes registered enough of a G-force to activate their car's medical alarm.
[59][60][61] The collision was referred to the stewards and Pérez incurred a five place grid penalty for the season's next race in Austria because they deemed him to have made an illegal manoeuvre that caused the crash.
Pérez said he maintained his braking sequence and line prior to the crash, "There was plenty of space on the left of my car to attempt a clean overtake, and I cannot understand why he had to scrape by.
Chilton incurred a three-place grid penalty for the upcoming Austrian Grand Prix for being deemed at fault for the accident.