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

If practice pace is anything to go by, this could be the most exciting session of the season. Mercedes looks genuinely slow - with all its customers also struggling in FP3 - while Ferrari and Red Bull have been leading the way so far.

I usually take practice with a pinch of salt but the gap to the front was so big it seems Mercedes is genuinely struggling here. That's probably more down to the nature of this circuit than a genuine swing in momentum, but still makes for a compelling weekend.

News from the other grid to start you off with - both Manor drivers face a five-place grid penalty for gearbox changes. So they'll still be starting from the back row.

Elsewhere, keep an eye on McLaren. Alonso has been absolutely manhandling the MP4-30 in practice so far, and has been eighth and seventh in the last two practice sessions. He was within 0.02s of Rosberg in FP3!

In this qualifying session, a Hamilton pole will tie Senna, a Ferrari pole will tie Senna, and a Red Bull pole will tie Senna. I kid you not

— Sean Kelly (@virtualstatman) September 19, 2015

One for the record books this evening, then.

Unless Mercedes is playing the greatest bluff in the history of F1, the world champions are genuinely concerned about their pace around here.

It appears Grosjean is wearing green overalls for this session....

Just over ten minutes to go until qualifying. This is the most excited I've been for a qualifying session this year, genuinely a hard one to call.

Mercedes still has a big lead in both championships but a strong result for Ferrari, coupled with a poor result for themselves, could have ramifications on how the team dictates strategy going into the next six races. Notably, whether it considers team orders or not.

Maybe that's getting ahead of ourselves. Was very telling that on Thursday, Hamilton made a throwaway comment that no-one was focussing on the fact Ferrari made a bigger step in Monza than Mercedes did.

That was his opinion, I might add.

New overalls for the Lotus boys.

.@XBOX!! pic.twitter.com/xuc64zcO38

— Lotus F1 Team (@Lotus_F1Team) September 19, 2015

Never know why teams don't have a bit more fun with their driver overalls. I remember McLaren's all-black number from Singapore a few years back, while Massa's 2006 Brazil garb lives long in the memory.

The lights are on, the circuit is lit up. We're just about ready for qualifying to begin!

The temperature has dropped slightly to 28 degrees Celsius because the sun has now gone down.

The light goes green and off we go. Rossi's Manor is the first out on track followed by the Williams drivers.

Hamilton heads out right in front of Raikkonen. Soft tyres for both men early, but will Mercedes feel the need to take super-softs before this session is over?

Rosberg now trundles out of the pit lane. He's not been happy with his set-up so far this weekend.

Big lock up from Bottas at Turn 13.

Bottas sets the first time of qualifying, a 1:48.094.

Team-mate Massa crosses three tenths down. Grosjean and Maldonado have both had trips into the escape roads around the circuit, but both have escaped without damage. Replays show a big, big lock up for Grosjean.

Verstappen crosses 0.065s behind Bottas to split the Williams drivers. Both Ferrari drivers on flying laps.

Raikkonen goes P1 with his first effort, a full second faster than Bottas' time. Soft tyres all round for the front runners so far.

Ricciardo now goes quicker, two tenths up on Raikkonen. Good lap from the Australian.

Switch of strategies on the McLaren but Alonso currently lapping quicker than Button despite having the slower compound. Button radios McLaren to ask what's going on.

Kvyat demotes Raikkonen but can't displace Ricciardo. He moves into second, 0.143s down on his Red Bull team-mate but Vettel is on an absolute stormer.

Vettel goes purple in all three sectors and that's a mighty, mighty effort from the four-times world champion. He crosses seven tenths quicker than Ricciardo in a 1:46.017.

Rosberg's first time has put him into fifth, Hamilton has come back into the pits without setting a time yet.

Rossi currently up on Stevens by 1.3s in the battle of the Manors.

Raikkonen goes green in all three sectors but is still nine tenths down on Vettel, and a tenth behind Ricciardo.

Button moves into fifth on the super-soft tyre as Ricciardo lowers his time to 1:46.692 - that's still six tenths behind Vettel. Ricciardo on the soft tyre.

Replays show Ricciardo sliding well wide on the final kerb for that last lap - it should result in that lap time being chalked off as all four wheels were over the line.

Vettel driving like a man possessed out there at the moment. Is this a glimpse of what we can expect from Ferrari in 2016?

Vettel can't improve on his time but how much more does Ferrari have to come from the super-soft?

Mercedes has sent both drivers out on the super-soft tyres. Hamilton currently in 14th after a lap which probably saw him get held up in a bit of traffic.

What an amazing turnaround since Monza for Mercedes. Doubt they would call it Mercedes, but you know what I mean...

Vettel tells Ferrari he's "fairly happy" with his first two runs. He's six tenths quicker than the nearest man.

Screens say everyone but Raikkonen on track currently has the super-soft compound on their cars.

Verstappen moves into second on the super-soft tyre, 0.446s behind. Hulkenberg third, 0.6s down. This is why Mercedes felt the need to take the super-soft so early.

Hamilton goes fastest on those super-softs, and then is knocked down by Kvyat who crosses four tenths quicker. Rosberg can't even beat Vettel's soft tyre time and has to settle for fourth!

Mercedes looking at the third row of the grid at this rate.

Raikkonen in a spot of trouble having not gone out on the super-soft...

Just over a minute left of this session. Alonso in eighth but Button currently hovering near the drop zone in 14th...

Ricciardo moves up to fourth on the soft tyres. Raikkonen improves to seventh on the soft tyre and that will be enough to go through to Q2.

Ricciardo moves up to fourth on the soft tyres. Raikkonen improves to seventh on the soft tyre and that will be enough to go through to Q2.

Raikkonen still half a second off the pace of Vettel on the same tyres...

Chequered flag drops....

Stevens jumps ahead of Rossi with his final run!

Button has been dropped into the bottom five...

Wow. Button scrapes through to Q2 by less than a tenth.

Looked like Button was giving that full beans in the final sector. Both he and Alonso have been throwing the MP4-30 around this circuit - a sniff of a strong weekend must be a big motivator.

Button's late lap means Nasr, Ericsson, Maldonado, Stevens and Rossi drop out of Q1.

That must be disappointing for Sauber, who came here with a big aerodynamic upgrade.

Replays currently showing Maldonado slipping and sliding his way through the Turn 11/12/13 sequence on a flying lap. He looked pretty scruffy out there. Still yet to confirm a 2016 seat, remember.

Maurizio Arrivabene looks cool and collected on the Ferrari pit wall.

Only the Ferraris and Ricciardo progressed through that session without needing to use a super-soft tyre. The sort of luxury usually enjoyed by Mercedes.

The clock goes green for Q2.

Bottas the first man out for the second session.

The track getting a little busier now. Ten of the 15 drivers out on track.

Siddhesh says: "Pretty sure someone replaced the Mercedes work Engine with a Honda. No other way to explain a 1s deficit. Either that, or Ferrari and Redbull found a time turner to get a years worth of development into their chassis!"

Team appears to be struggling with the adjusted tyre pressures, but this is the most technical circuit on the calendar. Whatever it is, it's a breath of fresh air.

Behind Merc, Ferrari and Red Bull, there is going to be an almighty scrap for the final four spots in Q3. Alonso said yesterday seventh-14th could be split by a handful of tenths.

Bottas clocks a 1:46.247 with the first lap of Q2.

Super-soft tyres from here on out now.

Some much-improved sector times from Mercedes as Hamilton goes into P1 with a 1:45.650.

Ricciardo then crosses in a 1:45.291! That's a huge advantage and we haven't even seen Ferrari yet. Kvyat lowers the target time even further, going three tenths quicker than Ricciardo.

Alonso can only manage tenth.

Button goes 12th.

Both Ferraris to come.

Raikkonen looks a bit sloppy through the final corner and can only manage P2, 0.161s down on Kvyat. Grosjean improves to seventh.

Lightning first sector from Vettel. He's on fire today.

Vettel hits a bit of traffic as he has to take the long way round Button's McLaren.

But it doesn't matter as Vettel goes into P1 with a 1:44.743.

The gaps to Vettel: Kvyat 0.236s Raikkonen 0.397s Ricciardo 0.548s Hamilton 0.907s Rosberg 0.910s Massa 0.958s Grosjean 1.062s Verstappen 1.125s Bottas 1.504s

Alonso and Button need to find some magic at the end of this session if they want their first Q3 appearance of the year. They are currently 13th and 15th.

A team that didn't reach Q3 at the last race is 0.671s quicker than Mercedes right now

— Sean Kelly (@virtualstatman) September 19, 2015

Vettel has the Marina Bay circuit all to himself at the moment but he appears to be easing his way back to the pits, and indeed he is.

Vettel returns and there's the usual lull between runs either side of Q3. Some vital laps coming up for several drivers on the cusp of the drop zone and in the drop zone. Could be some real shocks in this session behind the top six.

Ferrari-Red Bull has quite a good ring to it, doesn't it....

The Mercedes drivers head back out on track and they are in unfamiliar territory, nearly a second down on the lead.

Everyone but the top four head back out on track. There is a second between Perez in 11th and Ricciardo in fourth so you would assume they are all safe...

Rosberg asks Mercedes for a reminder to slow down immediately after his hot lap finishes. He's also taken a couple of turns on the front wing after struggling with his set-up all weekend.

Bottas improves on his time but that doesn't see him improve on tenth.

Looks like Sainz has clouted the wall somewhere on his lap as he crawls back to the pits with a broken rear suspension.

That may have saved Bottas' bacon as yellow flags come out for all the cars behind Sainz! Both McLarens will drop out - Alonso had just improved to 12th so he would have been eliminated anyway.

Just ran oh-so-slightly wide there and clobbered the wall coming out of Turn 19.

Just before that, Verstappen had jumped into P5 so he makes it through to Q3.

Dropping out - Hulkenberg, Alonso, Perez, Sainz and Button. Alonso will be disappointed after his performances in Q3 - seems his lap was compromised by Sainz's off so he may well have improved on 12th had that not occured.

Well, there's your first bit of drama from this session for you.

We'll have the quiet before the storm now. As it stands, Vettel appears to be on the cusp of Ferrari's first pole position since the 2012 German Grand Prix. Don't discount Red Bull yet.

Replays again of the Sainz incident show he just carries a tiny bit too much on the exit of Turn 19 and his rear tyre clips the wall. Game of inches, sometimes.

Raikkonen has to find three tenths if he wants any chance of challenging Vettel for pole. The German has been absolutely on it all day.

A smiley Button walking down the pit lane, waving to the fans. Alonso has kept his helmet. How much would he give to still be in Vettel's seat right now?

Alonso, the last man to take a pole for Ferrari, hasn't won a race since May 2013. Pretty staggering for such a great driver.

The lights go green again and Ricciardo leads Kvyat out on track. Hamilton not too far behind. This should be a cracking session.

At this stage you'd put your house on Vettel but how can the other three drivers behind him respond? Can Mercedes get themselves on the first or second row? We're about 10 minutes away from finding out.

Ricciardo starts the first flying lap of Q3. Let's see what the Red Bull drivers can do ... and I include Verstappen in that, because he made it through to this session in his Toro Rosso. He won't be on the front three rows but he's continuing to impress.

Raikkonen goes purple through the first sector...

Ricciardo then goes purple through the middle sector. The Australian is absolutely on it. Vettel now goes quickest through the first sector!

Ricciardo crosses in a 1:44.607.

Bottas is two seconds off Ricciardo, Kvyat is one tenth behind.

Hamilton aborts his first flying lap and heads into the pits. Seems he ran wide in the middle sector.

Raikkonen goes into second, just 0.06s behind Ricciardo...

Vettel takes provisional pole! 1:44.305 for the German driver.

Rosberg in P5... championship leader Hamilton has a huge job on his hands at the end of this session.

Rosberg told Merc will leave slightly more pressure in his tyres for the next run. "I don't really understand that [message] but OK," is the reply.

We have the usual lull in proceedings before the final Q3 laps. It's all looking very good for Vettel currently. Ricciardo and Raikkonen have to find a whole three tenths and then some.

Williams releases Bottas out just in front of Ricciardo's Red Bull. Track position crucial in these final moments.

Hamilton heads out, before Rosberg does the same. Raikkonen manages to get out in front of Rosberg as they trundle down the pit lane.

We haven't had a pole position by a non-Mercedes powered car since the introduction of these V6 turbos. That looks set to end in about two minutes' time.

Ricciardo needs a big middle sector if he wants pole position. Raikkonen goes purple in the first sector.

Bottas jumps ahead of Rosberg with his time. Ricciardo moves to within a tenth of Vettel but it's enough.

Hamilton puts himself into fifth. The run of poles ends but who will it be ended by?

Rosberg can't out-qualify Hamilton! Sixth only for the German.

Raikkonen can't improve on third and Vettel takes his first pole position in a year and a half!

Vettel still absolutely on it and he moves to a whole five tenths quicker than Ricciardo to put icing on that pole position. Wonderful stuff from the Ferrari driver.

Replays show Ricciardo absolutely throwing his Red Bull through the final sector, when he could clearly see he was down on the delta time he needed.

But star of the day is undoubtedly Vettel. What a lap that was at the end from the German and you could see him pumping his fists as he rounded Turn 1.

"Well done Daniel, you'll be able to see the lights tomorrow!" Horner says on the radio. "It's been a while!" is Ricciardo's reply.

Nice smile from Raikkonen as he congratulates Vettel on pole in parc ferme.

Tomorrow should be absolutely fascinating. Please be sure to join ESPN again for the Singapore Grand Prix.