Mark Gallagher
BBC Radio 5 live Formula 1 analyst

It is a kind of what we expected. Pre-season testing is nonsense because there are so many unknowns and now we are getting to build up a picture of how the season could be shaping up.

1) Lewis Hamilton (1:24.220) 2) Valtteri Bottas 3) Daniel Ricciardo 4) Max Verstappen 5) Kimi Raikkonen 6) Sebastian Vettel 7) Felipe Massa 8) Romain Grosjean 9) Nico Hulkenberg 10) Sergio Perez

Tom Clarkson
BBC Radio 5 live commentator

Sebastian Vettel didn't do a lot of running in the middle of the session because he had a problem with his DRS.

Mark Gallagher
BBC Radio 5 live Formula 1 analyst

Lewis Hamilton will want to put his marker down to his team-mate and has done that today. He will be aiming to make sure that in no two ways is Bottas going to challenge his supremacy in that team.

Image source, AP

So far so good for Romain Grosjean and Haas. The Frenchman is currently eighth, two seconds down on Lewis Hamilton's benchmark time but having done his best time on the supersoft tyre, with Hamilton having done his on the faster ultrasofts.

Just five minutes to go in first practice and the timesheet has a look of 2016 about it with two Silver Arrows leading the way.

Image source, AP

Paul Tosie: Working the night shift here in Hackney , give us a shout, Paul and Steve 

Tall Paul : Working night shift on an Ambulance in Leeds. Hoping @McLarenF1, external set fastest time and show us all that testing was a practical joke! 

Luke BGN: Hi guys, can you tell my fiancé Katie that she is keeping me awake listening to your coverage! Thank you. 

It's a 1:25.464 for Sebastian Vettel on the supersofts and he slots in sixth. 

Very early days, but has testing given us another Ferrari false dawn?

Image source, Getty Images

Andrew Benson
Chief F1 writer in Melbourne

Mmm. First practice and all that, fuel levels unknown etc, but where has that Ferrari testing pace gone?  

It's a 1:25.372s for Kimi Raikkonen. That's an improvement, but not enough to move him up from fifth. Surely, surely more to come from the Ferrari?

Sebastian Vettel has also peeled himself from off the floor at the back of the garage and is on the track once again, also with supersofts on his Ferrari.

I asked where Ferrari were and they have responded. Kimi Raikkonen is out on the super-softs for the first time. Let's see what they've got...

Tom Clarkson
BBC Radio 5 live commentator

Jolyon Palmer's Renault has a transmission problem. The car is up on stilts and won't be back out in the session.

Max Verstappen has crept into fourth with a 1:25.246,four tenths slower than his team-mate Daniel Ricciardo.

At the moment it is Mercedes-Mercedes-Red Bull-Red Bull at the top of the timesheet.

Ferrari, where are you?

It's 02:10 GMT and all is well at McLaren. Fernando Alonso has completed 15 laps so far and is currently 12th quickest. 

Image source, Rex Features

Sam Howes: Figured I might as well listen to the start of the new season... Seeing as I'm up finishing off Uni work anyway!...  

Thom Chapam:  Enjoying listening to the #bbcf1, external while I write my essay due at 4pm Friday. Perfect accompaniment to a late night student essay session.

So many of you writing essays into the dead of the night. At the risk of sounding like my parents.. why have you left it so late!?

Valtteri Bottas has a bit of a moment as he runs wide at the exit of Turn 12, keeps it together though and is back on his way with the minimum of fuss.

Still just the Mercedes duo to give those ultrasofts a go.

Bethonie Waring: What am I doing up at 2 in the morning? Questioning my life choices...

Christopher Sharp: Writing a presentation in London at 01:15am  

Sebastian Vettel is crouched down at the back of the Ferrari garage, watching Mercedes do their thing. He's done just five laps so far. 

Mark Gallagher
BBC Radio 5 live Formula 1 analyst

First blood to Lewis Hamilton. This is all new territory for Bottas and irrespective of pre-season testing, no easy challenge for the Finn for the season ahead.