Back at one of his all-time favourite tracks it was like old times for Hamilton, a seven-timer winner at the Circuit Gilles Villeneuve, leading a Mercedes one-two ahead of team mate George Russell (25) that offered signs and a bit of hope that finally a challenger to mighty Red Bull might be emerging.
While no one in the Mercedes garage is predicting victory on Sunday there were nonetheless plenty of smiles as Red Bull's championship leader Max Verstappen (25) placed sixth and team mate Sergio Perez (33) eighth.
"The car didn't feel bad but I think we've definitely got some work to do," said Hamilton. "It's just bumpy. I think everyone's having their struggles with the bumps.
"We've just got to improve our ride control and a bit of the balance through corners and I think we'll be alright.
"Overall the car is just a step forwards and I'm definitely feeling the improvements that we got in Monaco."
The upgrades in Monaco and Barcelona led to a double podium at the Spanish Grand Prix with Hamilton finishing second and Russell third behind race winner Verstappen.
And while the Mercedes men were back on top on Friday the outfit's technical director James Allison cautioned not to read too much into the result which was as much a product of strategy and luck with the weather.
"We chose, thinking that this rain was coming a little sooner than it came, we ran our long run at the beginning of the session and our short runs at the end," explained Allison. "Everyone else did it vice-versa, so we were doing our short runs when the track was at its best."
"I think there's plenty more to improve on the car before we get to qualifying and I think all we can read into it is that the car is in OK shape.
"But its not deserving of a one-two, because we just weren't running at the same time."
Red Bull has won all seven races this season, Verstappen taking five victories, and most observers expect that dominance to continue in Montreal.
Even Allison could not bring himself to make any predictions beyond things finally are all pointing in the right direction.
"I certainly loved the good result we had in Barcelona," admitted Allison. "That puts a smile on everyone’s face.
"Probably a little bit too soon to say that summer has arrived with that one swallow – but hopefully, we’ve turned a bit of a corner. I think this track is going to be very different in the challenges it places on a car but I think we’re gently on the up."
