Mercedes boss Toto Wolff says that the result of the Canadian Grand Prix shows that his team no longer enjoys any sort of clear advantage in the Formula 1 world championship.
Montreal has been a happy hunting ground for the Silver Arrows in the past, having won the last three races in succession.
But that wasn't the case on Sunday, when Sebastian Vettel dominated the race. He led Valtteri Bottas from pole to chequered flag to deliver Ferrari's first win at Circuit Gilles Villeneuve since 2004.
Red Bull were also very much in the mix, with Max Verstappen and Daniel Ricciardo both beating six-time Montreal winner Lewis Hamilton.
Wolff admitted that the result had been "a major wake-up call for every single member of the team".
"We came to Montreal expecting our car to be really strong. And we are leaving seeing we haven't been where we thought we should be.
"You can't come to Montreal and think it's going to be a walk in the park, because that's the kind of wake-up call you get."
"It's a three-way fight, six cars can win races. You can't take anything for granted," said Wolff as he digested the outcome. "Somehow this year the margins have become so tight: five cars within a tenth.
"This is why this year's championship is going to be decided by the ones who make the least mistakes," he pointed out.
He added that it marked an end to "the historic pattern of cars being strong on certain circuits and then weak on others."
Mercedes has improved on some of its weaker circuits so far in 2018, but not by enough to make up for the loss of their advantage elsewhere.
"I still think we are not pretty good in Monaco or Singapore," Wolff conceded. "That may be the odd outlier, but you need to expect people to be strong everywhere."
Mercedes went into Montreal on the backfoot after having to postpone its plans to introduce a new power unit at the race. The decision - due to reliability concerns - meant Bottas and Hamilton were using older engines that had already completed six full races.
"We were expecting to have the engine here and then on the last long run we spotted a potential issue," he confirmed. "I'd rather have it in the car on Friday morning, run it without problems, and then confirm it."
Wolff admitted that the season could well be won by the team that "brings the best development onto the engine on every single weekend - and that is the new reality."
"You have to come to the weekend, all your preparation work has to be spot on," he added. "There's no time to be lost in terms of preparation on the Friday because it's going to come and bite you."