The defending champion was consistently at the forefront of the times at Montreal, which makes its first appearance on the calendar since 2019.
Verstappen kicked off the weekend during which he is set to make his 150th GP start by lapping 0.25s ahead of the fastest Ferrari, with Fernando Alonso third to pip Sergio Perez and Charles Leclerc.
While the threat of rain was only calculated at 20% for the session, the looming gray clouds led to a flurry of on-track activity as soon as the one-hour countdown started.
Yuki Tsunoda was followed out into the windy conditions by the Alfa Romeos and Daniel Ricciardo as only the Williams duo and Alonso initially stayed put in their garages.
And of those to head straight out, all bar Tsunoda and Leclerc (both on softs) emerged sporting a set of the yellow-walled medium compound C4 Pirelli tires.
The initial markers flirted around the low 1m20s and high 1m19s effort before Verstappen started to markedly lower the pace as he posted a 1m17.991s to sit 1.4s clear of Lewis Hamilton.
Valtteri Bottas, Ricciardo and Sainz all lapped around a second adrift of Verstappen before Hamilton cut down to a 1m18.613s to close the gap to six tenths.
All 20 cars had ventured out after six minutes to maximise track time following the Thursday evening downpours, before Bottas climbed to the top with his 1m17.902s effort.
Verstappen at this point was on a cool lap to reenergise his tires but then promptly smashed the fastest second and third sectors to retake first place on a 1m16.507. That duly decimated Bottas’ time by 1.4s.
The first meaningful run from Monaco winner Sergio Perez moved the Mexican half a second in arrears of his teammate until Verstappen teed up another flying lap.
The RB18 driver completed a sector clean sweep at that stage to dip down to 1m15.799s, initially pushing him 1.2s clear of Perez at the top of the leaderboard.
Verstappen found another nine hundredths with his next attempt before Perez ran to the top after 14 minutes thanks to a 1m15.660s, which promptly placed him four hundredths ahead.
After the hectic start to date, track activity virtually died out after the first third of the session before Perez then Verstappen switched to the soft tires after 28 minutes.
However, Verstappen made a swift return to the Red Bull garage as a rear anti-roll bar glitch caused his inside wheel to lift.
But after Sainz had gone top with a 1m15.441s to sit a tenth clear of Perez, Verstappen – despite conceding the first and second sectors to his Ferrari rival – set the best time of the session.
He ran to his pacesetting 1m15.158s to sit pretty by 0.25s over the Spaniard before a final switch to mediums for the field as they sought to understand their respective race pace.
Behind Verstappen, who complained off clipping as his rebadged Honda engine greedily consumed its electrical hybrid assistance, and Sainz was Alonso aboard his Alpine.
The two-time champion had played its fast and loose out of the final corner as a bout of oversteer took him right up to the heralded ‘Wall of Champions’.
Perez ran to fourth as Leclerc, who retired while leading the Azerbaijan GP last time out with a power unit failure, was half a second adrift of Verstappen as he ran to fifth.
Leclerc entered the session with a new internal combustion but retained a used turbocharger to leave a looming grid penalty unconfirmed at this stage.
George Russell was sixth-quickest aboard his Mercedes while Lance Stroll kicked off his home race by leading a decent Aston Martin charge in seventh.
Hamilton, who had complaints over rear car balance as Mercedes ran an experimental floor solution, split the Astons as Vettel ran to ninth.
Ricciardo, meanwhile, completed the top 10 over Pierre Gasly while Lando Norris clocked 12th but ran 12 laps short of his teammate as McLaren spotted an issue with the Brit’s car.
Alex Albon headed Tsunoda and Ocon, whose session was interrupted early by a right-front brake fire caused by detritus working its way into the duct.
Bottas led a subdued Alfa Romeo front in 16th, while Mick Schumacher, Nicholas Latifi and Kevin Magnussen completed the order.
As per tradition in Canada, the local groundhogs enjoyed a high-risk game of dodging the cars as they dashed across the track.