While not given to hyperbole, this afternoon's qualifying session has all the makings of a thriller.

This morning's practice session saw the top four - Verstappen, Vettel, Raikkonen and Hamilton - covered by just 0.107s.

This marked three successive session in which Verstappen dominated, the perfect answer to his various critics.

It also marked a significant improvement for Ferrari, certainly compared to yesterday, when the red cars appeared to be struggling.

Then there was Lewis Hamilton. Having steadfastly avoided the hypersofts, much like his Mercedes teammate, the Briton eventually bolted on a set knowing that the rules dictate they must be used in Q3. Despite his best efforts, which included several warm-up laps, he could only manage fourth, albeit just 0.107s off the pace.

However, while he will no doubt seek to qualify on the ultrasoft this afternoon, it appears highly unlikely that he'll be able to grab pole. Then again, we have learned never to write-off the Briton.

Ricciardo and Bottas completed the top six - as they so often do - ahead of a midfield pack that is almost volatile such is the ferocity of the competition and the ever changing form.

Force India looks best overall, while Renault looks to have the edge over Haas, McLaren and Toro Rosso.

This morning's session was the first not to feature a red flag, but in the intensity of this afternoon's battle for a decent grid position there are sure to be some near misses and almost certainly a degree of over enthusiasm.

Ahead of Q1, the air temperature is 22 degrees C, while the track temperature is 43 degrees. It remains bright and sunny.

In late news, Honda reports that Gasly has been switched back to the old power unit after reporting a loss of power at the end of this morning's session.

The lights go green and Magnussen leads the way with Leclerc right behind.

As Grosjean exits his garage a huge cloud of smoke billows from behind and follows him down the pitlane. "Stop the car, that's it" he is told. Following the instruction he waits as his crew run to his rescue.

Sirotkin and Ericsson head out, everybody on the hypers thus far.

Magnussen posts 14.237 and Leclerc 14.543 as proceedings get underway.

In the Haas garage, Grosjean remains in his car as his crew swarm over the back.

A 14.203 sees Sirotkin go quickest, but he won't be there for long, Vettel is on track.

Indeed, the German stops the clock at 12.110, over 2s quicker than the Russian's best.

Leclerc gets it wrong at T1 and has to use the 'alternative route'.

As Magnussen improve with a 13.374, Gasly goes third with a 13.785, only to be demoted when Raikkonen crosses the line at 12.050.

Bottas and Hamilton head out as Stroll goes fifth with a 14.007.

As Ricciardo heads out, Vettel goes quicker in the first two sectors, finally crossing the line at 11.824.

Ricciardo goes fourth with a 12.763, the Australian getting just a little too close to the walls for comfort.

Ocon posts 12.643 to go third but is demoted when Bottas posts 12.523.

Raikkonen improves with an 11.725 as Hamilton does well not to go off at T6.

Verstappen goes quickest in S1, finally crossing the line at 12.810 to go third.

Hamilton improves to fourth with a 12.268 following his previous very scruffy lap.

Vettel retakes the top spot with an 11.710.

Like his teammate, Bottas is quickest in S1 but can only mange PBs in the final sectors, the Finn crossing the line at 11.950 to go third.

"I hit the wall, I hit the wall," reports Ericsson, "my car is broken." Though he is able to continue he is told to pit.

Verstappen really pushing, indeed pushing too hard and almost losing the car as he seeks to improve. He subsequently pits after flat-spotting his tyres.

With less than four minutes remaining, Stroll, Leclerc, Sirotkin, Ericsson and Grosjean comprise the drop zone. Alonso and Magnussen are hovering.

Clearly struggling, Stroll misses the final chicane, his tyres lighting up in the process.

Magnussen improves to twelfth with a 12.980 as teammate Grosjean finally climbs from his car.

All eye on Alonso as he begins his final lap, the Spaniard currently 16th. PBs in the first two sectors are followed by another as he crosses the line at 12.979 to go 14th, thereby demoting Gasly to the drop zone.

Quickest is Vettel, ahead of Raikkonen, Hamilton, Bottas, Verstappen, Ricciardo, Ocon, Hartley, Magnussen and Sainz.

We lose Gasly, Stroll, Sirotkin, Stroll and Grosjean.

As we head into Q2, the big question is whether Mercedes, and Red Bull, might opt to get through on the ultrasofts, the German team, in particular, clearly having a hard time of it on the hypers.

Magnussen is first out, followed by Raikkonen, who is on the ultrasoft. Vettel is another early riser.

The Mercedes duo head out and like the Ferraris they are on ultras.

Raikkonen gets proceedings underway with an 11.620 but Vettel subsequently posts 11.524.

Quickest in the first two sectors Hamilton makes a mistake in S3 and as a result can only manage third (11.740) only to be demoted when his teammate posts 11.514 to go top.

Magnussen is fifth and Leclerc sixth.

Both Bulls head out on the hypersofts. Ricciardo goes fifth (11.835), but is then demoted when Verstappen posts 11.472 to go quickest.

Ocon goes seventh (12.300), ahead of Magnussen, Hartley and Vandoorne.

A 12.097 sees Sainz go seventh as the battle for best of the rest continues.

Hulkenberg can only mange tenth as he stops the clock at 12.521.

In 13th and 14th, the McLaren pair are separated by just 0.004s.

With 3:30 remaining, Leclerc has the track to himself... but he's about to have company.

Indeed, Bottas, Hamilton, Raikkonen and Vettel head out on the hypers.

Leclerc goes thirteenth with a 12.661, leaving the rest, all 14 of them, to get on with it.

Magnussen improves to 11th with a 12.606.

Vettel posts a PB in S1 but loses pace in the second sector. However, he aborts the lap after finding himself behind a traffic jam at the final chicane as drivers back off before a final lap. "This is ridiculous," complains the German. "I am doing 300 and here are three or four cars doing 80." Indeed, the on-board footage reveals the potential for disaster.

Alonso can only manage 14th, while teammate Vandoorne remains 15th.

An 11.434 sees Ricciardo go top, as the Mercedes duo opt to abort their laps.

Quickest is Ricciardo, ahead of Verstappen, Bottas, Vettel, Raikkonen, Hamilton, Hulkenberg, Sainz, Ocon and Perez.

We lose Magnussen, Hartley, Leclerc, Alonso and Vandoorne.

Check out our Saturday gallery from Montreal, here.