"We came to Montreal thinking our auto would be strong", Mercedes boss Wolff said.
Cue some serious work overnight, both in Montreal and at Ferrari's Maranello base with reserve driver Antonio Giovinazzi putting in the miles in the simulator.
It was also the 50th career victory for the 30-year-old, who was a four-time Formula One champion in his days at Red Bull Renault.
When asked if he was anxious errors could start creeping in as a result of an intense fight, he said: "I think you need to get the right balance between pushing development very hard, adding performance to the vehicle and at the same time keeping reliability".
In contrast, Ferrari arrived with their new engine, complete with upgraded fuel, and the team felt it delivered a gain, one that would be particularly useful on a power track such as Circuit Gilles-Villeneuve. "Also myself didn't get the rhythm yet so missing a little bit of the laps but overall we tried to go through the programme as good as we could".
Over the expected finish line, after 70 laps, the gap between the pair was just 0.1s in the Finn's favour, however, the race was officially ended two laps early due to celebrity model Winnie Harlow waving the chequered flag prematurely.
"I'm just so happy that I finished as from the start I was down on power and my engine was saying that it was over temperature and I couldn't get them down", he said. The fact that a season could sway through reliability, I don't think anyone wants to see that.
Thanks to his strong performance, Vettel moves back into the lead spot in the 2018 Drivers' Championship with 121 points. I think they peaked a bit early, but majority are men so it might happen.
All this left Vettel in command after 40 laps, 5.7 seconds clear of Bottas with Verstappen third ahead of Ricciardo, Hamilton and Raikkonen. "But we have to say that Ferrari's auto, as a package, is unbelievable".
The battle for "best of the rest" saw a straight fight between Esteban Ocon in the Force India and the two Renaults of Carlos Sainz and Nico Hulkenberg.
It was a short day for the lone Canadian as Stroll's Williams slid across the track and rammed New Zealander Brendon Hartley of Toro Rosso into a wall. Both cars were badly damaged but the drivers escaped uninjured.
"The only feeling I have is that we have to wake up".
Here's what else we learned in the Canadian GP.
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