A lot could still happen in this race, as the opening 40 laps have already demonstrated.
But Verstappen is pulling away from Russell and looking in control out front. He leads Russell by nearly three seconds.
Norris is 1.5s adrift of Russell, with Piastri and Hamilton close behind.
Albon has completed an impressive double overtake on Ricciardo and Ocon.
First he blasted past Ricciardo's RB before catching Ocon under braking at the final chicane and cheekily and boldly sticking the nose of his Williams up the inside to grab ninth.
Brilliant stuff from Albon!
Leclerc has had to concede defeat as the rain gets heavier. Ferrari's gamble has not worked out and he pits again for intermediate tyres. He was already last and is now miles behind the field.
This is not turning into a good weekend for Leclerc and Ferrari.
We are back racing on Lap 30 as Verstappen holds his lead from Russell into Turns 1 and 2.
Ferrari have gambled by pitting Leclerc and putting him on hard tyres...
Norris now pits but he has lost the lead to Verstappen. He's also dropped behind Russell.
The Safety Car was Norris and McLaren's best friend in Miami, but not today.
Lap 25/70
Sargeant hits the wall at Turn 4 and the Safety Car is deployed.
Everyone but race leader Norris pits for fresh intermediate tyres.
Hamilton gets ahead of Alonso in the pits!
Lap 21/70: Norris takes the lead!
A brilliant pass around the outside of Russell on the run to the final chicane.
Russell then skips the chicane and loses another position to Verstappen.
The polesitter falls to third.
Lap 20: Norris is through and up to second, using DRS to get past Verstappen's Red Bull!
He's now right behind Russell.
The track has just been declared dry enough to use DRS. This is good news for Norris in his battle against Verstappen.
Verstappen runs wide over the run-off at Turn 1 and frops a couple of seconds to Russell, giving the Mercedes man some much-needed breathing space.
That mistake has now put Verstappen into the clutches of Norris' McLaren, who is within a second of the Red Bull driver and currently the quickest man on track.
A clear dry line is appearing now. But off the racing line, it's still wet. The drivers are having to hunt for the wet stuff on the straights to cool their tyres, with Russell even suggesting it could soon be time for slicks.
The sun is coming out and it's getting brighter in Montreal, but Mercedes tell Russell they are anticipating more rain in the next 15 minutes or so.
Some 25 seconds off the race lead, old foes Alonso and Hamilton are continuing their battle over fifth place.
Alonso holds the position at the moment, with Hamilton getting close on several occassions but not close enough to mount an overtake.
As expected, Ricciardo has been penalised for a false start. It's a five-second time penalty for the Australian, who is now up to seventh.
Verstappen is now within one second of Russell as he continues to chase down the Mercedes.
But he won't get the DRS boost in these wet conditions.
Uh oh. The stewards have noted Ricciardo for a possible false start.
A penalty could be on the way for the RB driver, who is running in 8th.
Verstappen is flying now he's got his inters up to temperature. He's just posted a fastest lap to reduce Russell's lead to 1.6 seconds.
Sargeant goes straight on at Tunr 6 and hits the wall!
But he is able to reverse out with damage to his front wing and continues in the race.
That avoids the need for a Safety Car.
"We have issues on the engine."
Not the radio message Leclerc would like to hear!
He is continuing for now in 11th place currently.
The rain is just starting to ease up and there's blue skies around.
If the intermediate runners can stay on track, they might yet be okay.
Meanwhile, Magnussen is now fourth, but how long will the conditons stay wet enough for full wets?
Lap 3/70: Magnussen is flying!
He's scything his way through the fold as he now passes Hamilton and Alonso to move into fifth.
Hulkenberg is also making good progress and is up to ninth.
They are on the right tyres at the right time
Hamilton managed to get past Ricciardo on that first lap, while Magnussen is flying on the wet tyres. He's already up to sixth!
Lights out and the Canadian Grand Prix is go!
Russell holds his lead from Verstappen into the first couple of turns.
Russell leads the field away for the formation lap. It's nearly time to go racing in Canada!
There are rain cells all around the circuit and the rain is coming down again.
Everyone on intermediates bar the Haas duo, who have gone for full wets.
During his grid walk, Martin Brundle spoke to Safety Car driver Bernd Maylander, who said he expects a normal standing race start unless further rain falls.