Sebastian Vettel was pretty happy with his effort to take pole in Montreal - a lap record at Circuit Gilles Villeneuve.
"I was a bit confused". "He just ran me out of road", said the luckless Hartley.
"Some of the marshals were already celebrating", he said. I just thought it was going to fail.
"We extracted the best we could out of qualifying".
It was the Italian team's first Canadian GP win since Michael Schumacher in 2004, a race Vettel watched on television as a teenager at home in Germany.
Hamilton had been hoping for a record seventh Canadian Grand Prix pole, at the track where he took his first win in 2007, but instead was out-qualified by Finnish teammate Valtteri Bottas who joined Vettel on the front row.
Hamilton had held on to fourth position at the start but an overheating engine and intermittent losses of power prompted Mercedes to pit him earlier than planned. I think they peaked a bit early, but majority are men so it might happen. "Everybody needs to assess how to improve performance ... those marginal gains are going to make all the difference".
While Vettel made a clean getaway from the start, with Verstappen nearly passing Bottas, there was chaos behind when Williams' Canadian Lance Stroll squeezed Toro Rosso's Brendon Hartley into the wall.
On the restart, Sergio Perez skidded onto the grass but managed to straighten himself out and rejoin the race.
"Tell them not to wave the checkered flag when it's not done yet", he radioed back.
Ricciardo said after qualifying the strategy call will allow him to be aggressive in the early stages of the race and give him the chance to gain crucial track position on his rivals. "It's just a day to remember the great Gilles Villeneuve". "It's nice to become part of that story, hopefully a little bit more in the future".
Bottas finished second for the fourth time in seven races this season.
Mercedes said they had detected a fault making the vehicle run hot in the opening stint and added cooling at an early pitstop to help the situation.
"We were briefly talking about what we wanted to do, trying to figure everything out". There's been many occasions it's been close. We just keep doing what we are doing, keep our heads down, keep motivated and keep pushing because they will falter.
Vettel won the first two races of the year but did not return to the podium until his second-place finish in Monaco last race.
Verstappen dominated practice after his "headbutt" threat in Montreal.
Two-time world champion Fernando Alonso is in 14th position.
It was also a short day for Stroll, a Montreal native who locked up with Hartley heading into Turn Five on the first lap.