Hamilton also had a brief engine worry during FP3, however Mercedes confirmed he had simply suffered a 'derate' and said there was no cause for concern heading into qualifying.

Hello and welcome to ESPN's coverage of qualifying for the Canadian Grand Prix.

The big news coming into qualifying is that Jenson Button will miss this session entirely due to an engine change. The McLaren driver stopped at the end of FP3 with an ERS-related issue. Fernando Alonso had an engine change of his own this morning - a bad day for Honda so far.

We haven't had a chance to see enough from Ferrari this weekend to know just how big a step (if any) it has made with that upgraded power unit. This afternoon will give us confirmation of its one-lap pace. Long run pace looked good in FP1 and FP2 on Friday.

Max Vestappen will also serve a 15-place grid penalty after qualifying today, a culmination of his Monaco punishment and for the engine change Toro Rosso undertook this morning. That moved him onto his fifth power unit of the year. Read how that penalty will convert into time penalties if he doesn't qualify in the top five - click here

My money is still on a Mercedes driver being on pole position, but its the cars directly behind that will be interesting. Splitting the Mercs could make for a very interesting race if you're Ferrari.

Behind the leading pair, it seems pretty obvious you want a Mercedes power unit strapped in behind the driver. Lotus and Williams looks to be the best contenders for the third row on the grid, while Force India has been strong all weekend so far.

No grey skies around so no chance of yesterday afternoon's torrential rain.

Sauber sounds confident it can get Felipe Nasr back out for this session after his bizarre crash in FP3. Looked like a lot of damage on that car so a brilliant job from Sauber if he can get out there.

We've got five minutes until the green lights go out.

It's 16 degrees out there, with a track temperature of 42 degrees. It's pretty chilly and there's been a bit of wind here consistently all day.

There's a sign in the grandstand at Turn 1 saying: "Lewis is top ... Why pit stop?" referring to the blunder in Monaco.

Work still going on in the Sauber garage to fix Nasr's car, but the Brazilian rookie has his helmet and race suit on.

Green light goes off and Alonso is the first man down the pit lane, but he does a practice start and gets passed by Hamilton.

Really flurry of activity out there early on. Fifteen cars out there early on.

Alonso absolutely throwing his MP4-30 through the second chicane and he gets very close to the wall. The Spaniard the lone gunner for McLaren today with Button watching from the sideline.

Alonso hanging on to the back of his car as he passes the Wall of Champions.

I could watch on boards of Alonso all day.

Early problems at Ferrari? Vettel complaining about an issue and returns to the problem. MGU-K issues this morning, is this a repeat?

Team-mate Raikkonen the early pacesetter with a 1:17.403, but Hamilton goes a second quicker.

Rosberg the next man across the line, he's six tenths down on Hamilton. All these early runs on the soft tyre.

Raikkonen improves on his next lap, a 1:16.649 - putting him second. Hulkenberg currently fourth, just eight tenths off Hamilton...

...But Hamilton was on an absolute flyer, going green, green and purple to shave nearly half a second off the target time. The new benchmark now 1:15.979.

Pole last year a 1:14.874 from Rosberg.

Rosberg puts himself in second with a near-identical time to HAmilton. Big gap between Mercedes and Ferrari so far, Raikkonen a full six seconds down.

Grosjean eyed fifth yesterday and that's where he is after that lap, a 1:16.928.

Verstappen and Sainz currently sixth and seventh. Hamilton on another flying lap, going purple in the first two sectors.

Hamilton loses the back end coming into the final corner but somehow keeps it together.

Maldonado has had a spin at Turn 1 - just after crossing to go third. Some brave marshals give him a push and get him started again.

Bottas jumps above Maldonado as Rosberg goes P1 by 0.002s.

Raikkonen re-claims third, three tenths off Rosberg. Lots of activity out there with the track getting quicker and quicker.

Vettel currently without a time but he's still sat in the car - it sounds like his engine is being fired up so he should re-appear soon.

Nasr is out on the supersoft tyre, which should prompt a lot of the midfield runners to follow suit.

Masr, Stevens, Merhi, Vettel (no time) and Button (not in this session) in the drop zone.

Seeing replays of Hamilton going over the sausage kerb at the final corner. Quite a clout. We saw him earlier holding on to the back end through that corner, so clearly the world champion really pushing the limits at that part of the track.

The screen has come back down in the Ferrari garage. The clock is ticking down - we're into the final five minutes so Ferrari needs to find a solution soon.

Hamilton clambers out of his car, Mercedes seems pretty content with the time the world champion has set. We'll see supersoft runs from Bottas (fourth) downwards, I'd say.

Vettel's Ferrari engine definitely sounds slightly poorly. They're trying to fire the thing up. As I said earlier, he had MGU-K problems in FP3.

Vettel heads out! Supersofts bolted on, so he should be in the next session if he has a clean lap.

Grosjean goes P1 on the supersofts, 0.060s quicker than Rosberg's soft tyre run.

Hulkenberg moves into fifth on the supersoft tyres. Nasr climbs to 12th, he could still be in trouble.

Vettel has started his flying lap but he has a wobble coming out of Turn 2.

"No power, no power, unbelievable!" Massa complains. Williams tells him to keep pushing - he's currently in the drop zone.

Vettel looks good to escape the drop zone, meaning Alonso is at risk.

Vettel can only manage 16th! That's not good enough to get out of the drop zone. Looks like Massa has bailed out of his lap too, so he'll join the Ferrari man.

I think Vettel crossed in time for another lap, though...

He did make the line in time, and he's gone green in his first two sectors....

Alonso improves on his time in 15th.... Vettel can't improve! Vettel drops out of Q1!

Well then - no-one expected that. Alonso beating his Ferrari replacement to 15th.

Vettel's radio message was bleeped out...

Correction on earlier, it's MGU-H which Vettel has been lacking, not MGU-K. Lots of turbolag on that lap, I imagine.

Replays show Massa locking up at the hairpin.

Dropping out of this session, Vettel, Massa, Merhi, Stevens and Button (no time).

Grosjean fastest in that session, albeit on the supersoft tyre. Rosberg's time was set on the soft tyre.

Compared to team-mates, Raikkonen finished sixth, Bottas in tenth, but I don't think either man came back out for supersoft runs while a lot of others in the top ten did.

Q2 is under way.

The times coming thick and fast now. Maldonado goes P1, but then is beaten to it by team-mate Grosjean's 1:15.916.

Hulkenberg goes into second, 0.150s off Grosjean. With one Williams and one Ferrari already out of the equation, Q3 could be interesting for Lotus and Force India.

Raikkonen gets oh so close to the wall on his first Q2 run and goes P1 with a 1:15.602. Perez slots ahead of his team-mate. The Mercedes cars all in very good shape here.

Seeing a replay of Maldonado locking up into Turn 1.

Both Mercedes drivers are out on track.

Woah. Hamilton lowers the benchmark to a 1:14.661. Rosberg crosses just 0.012s behind. Raikkonen a massive nine tenths back in third.

Bottas goes best of the rest in third, albeit 0.845s down on Hamilton.

"Why are we not running again?" asks Rosberg. He's told Mercedes wants to save a set of tyres. They're safe and sound in P1 and P2.

Maldonado puts himself fifth, ahead of team-mate Grosjean.

The current drop zone: Sainz, Verstappen, Nasr, Alonso, Ericsson.

Hulkenberg has just put himself safely into Q2, improving to a 1:15.706.

Replay shows Nasr bouncing over the sausage kerbs. Radio says he was looking good to escape the drop zone until then.

We're into the final minute. Perez getting close to the wall at Turn 4, he's absolutely throwing his car around too.

Perez doesn't improve on his time but he crosses with 10 seconds to spare. He may not need to improve, though...

Alonso wrestles his car through the final corner and moves up to 13th.

Ricciardo stays ninth. Verstappen moves to 12th, albeit before a grid penalty. Kvyat saves himself from the drop zone with a last-gasp lap to relegate Sainz into the drop zone.

So, the five cars in the drop zone are Sainz, Verstappen, Ericsson, Alonso and Nasr. Only one Mercedes engine has been eliminated so far.

12th for Verstappen means he'll start at the back of the grid, with a 10s race penalty hanging over his head, if my calculations are correct.

Got to comend McLaren-Honda for interacting with fans with these twitter accounts. And he/she/it is spot on about Alonso, he was driving that car by the scruff of the neck in Q2.

Here we go then, Q3 - it's Hamilton v Rosberg for pole but lots of surprises up for grabs in the battles behind. All the Mercedes customers will fancy their chances of having one car on the second or third row tomorrow.

I'd love to see Grosjean put the Lotus on P3, but it could be an all-Finnish second row.

The green light comes on and Q3 is up and running.

Seven cars out there in the early sessions. This the all-important 'banker' lap. This is where driver skill very much comes into play, a great lap could be the difference between third and seventh this afternoon for some of these guys.

Twitter seems to have stolen something I was saving for later - Hamilton, in car #44, is going for pole position number 44 of his career.

Grosjean and Ricciardo the only men remaining in the garage.

Hulkenberg sets a 1:16.110 on used supersofts.

Raikkonen takes P1, a 1:15.126. Maldonado slots in behind Raikkonen, two tenths behind. Looks like a new set of supersofts for the Lotus man, good lap.

Hamilton on his first flier of the session.

Hamilton kisses the Wall of Champions and takes provisional pole with a 1:14.393.

Rosberg doesn't get as close to the wall as Hamilton and he crosses three tenths behind his team-mate. He'll get another chance to beat his team-mate later.

Grosjean currently on his first flying lap.

"I didn't have grip on the rear," Rosberg tells Mercedes.

Mercedes says it expects his next set to be much better grip-wise.

Grosjean moves into fourth, behind former team-mate Raikkonen but ahead of current Lotus chum Maldonado. He's eight tenths off Hamilton.

We now have the usual lull in between the first and final runs. Every car in the garage. Only Ricciardo yet to set a time.

There's a grumbling turbo in the pit lane as Bottas heads out, followed by fellow Finn Raikkonen.

You feel both Mercedes drivers have more in the tank for a better lap. Ferrari tells Raikkonen he has fuel for two hot laps.

That will give Raikkonen plenty of time to warm up his tyres. The Lotus drivers head down the pit lane side-by-side. What on earth is happening there? Maldonado eventually yields.

Replay shows Lotus released both men at the same time. That was a bit of a mess.

That's what happens when you spend so long not having both cars in Q3!

Raikkonen goes green on first two sectors on this first lap of his.

Raikkonen improves on third fastest, but he's still 0.621s down on Hamilton. He's got two tenths in hand on Grosjean.

Into the final half a minute so this is it.

Hulkenberg can't improve on seventh but he crosses with time left on the clock, if he has enough fuel.

Bottas moves into fourth but can't topple Raikkonen. Rosberg's had a poor lap, Hamilton goes purple in the middle sector...

Hamilton doesn't improve on his time.... and neither does Rosberg! Hamilton takes pole number six of the season.

Replays show Raikkonen JUST keeping the car out of the wall at Turn 4.

Grosjean and Maldonado lock out the third row of the grid. Hulkenberg gets seventh, and he has two Red Bulls in between himself and team-mate Perez.

Rosberg ended that session by saying "What a rubbish end of qualifying!" Sums up the situation he's in where rubbish qualifying still puts you P2.

That's all we have time for this afternoon. Thanks as always for joining me and please do come back tomorrow when we see if anyone other than Rosberg can take the fight to Hamilton.