Mark Gallagher
BBC Radio 5 live Formula 1 analyst

He hit the wall with the right rear first and then the front right joined in.Desperately disappointing for Lance Stroll and the Williams team. A great deal of work to be done on that car.

Red flagpublished at 03:51 Greenwich Mean Time 25 March 2017

03:51 GMT 25 March 2017

Red flag!

Lance Stroll smacks the wall at Turn 10 side on.

It's a great time for Renault as Nico Hulkenberg does a 1:25.063 to move ahead of Red Bull and into fifth.

Image source, Getty Images

Mark Gallagher
BBC Radio 5 live Formula 1 analyst

Sebastian Vettel is four tenths quicker than the two Mercedes and suddenly it looks like Mercedes have a battle but we all need to stay calm. The reality is none of us ever know what is going on in front of us because drivers can have different engine modes. There are lots of variables at play, but maybe these next 15 minutes can give us a clearer indication of what to expect in qualifying.

Sebastian Vettel has beaten the record he set in 2011 with that time, but what can Mercedes do?

Valtteri Bottas crosses the line in 1:23.459, 0.479 seconds slower than Vettel and Lewis Hamilton is even slower! He does a 1:23.870, although looks to have made a mistake in the middle sector that cost him a bit of time.

Ferrari, though, are finally showing the pace we all hoped they had hiding away.

Image source, AP

Big lap from Sebastian Vettel! He goes six tenths quicker than Kimi Raikkonen to retake top spot with a 1:23.380. 

Meanwhile, Lewis Hamilton and Valtteri Bottas are out there now on a new set of ultrasofts, so we should get a clearer indication of what to expect in qualifying...

Image source, Rex Features

Kimi Raikkonen sneaks ahead of Sebastian Vettel to go top of the pile. He's one thousandth of a second quicker than his team-mate. 

Andrew Benson
Chief F1 writer in Melbourne

Red Bull did not have an easy day on Friday. Team boss Christian Horner said on Thursday he suspected they would be the third quickest team this weekend and that’s the way it is working out so far. More concerning will be the size of the gap. A second off Lewis Hamilton looks bad, but half a second off the Ferraris and Valtteri Bottas is perhaps worse - and they were the same margin off in race trim, too. In fact, Daniel Ricciardo, the only Red Bull to do a race run after a troubled day for Max Verstappen, was 0.4secs behind the impressive Toro Rosso of Carlos Sainz. 

Horner said the drivers were not happy with some of the set-up choices the team had made for the second session, and indeed they were not. “This morning was promising,” Ricciardo said. “We tried a few things this afternoon. It’s fair to say they didn't work as much as we'd like, so we'll probably go back a bit and then understand what we can do better. Mercedes is quick but it's more Lewis at the moment than Valtteri. I think with the right set-up and the right lap in qually, we can mix it with Ferrari. If Lewis does a perfect lap with his car, then that'll be a stretch to take pole - but we're not too far off.”

Daniel Ricciardo slips into a set of ultrasofts boots and heads on out for a quick lap. I saw quick, it isn't really as he does a 1:25.092, which is a second off the Ferrari benchmark. 

I'm still not sure what to expect from Red Bull this season.

Image source, Getty Images

We've had all 20 drivers on the track now. Fernando Alonso has no time for any installation lap shenanigans and gets stuck into timed laps, his first a 1:26.556 which puts him P14.

It's a 1:24.542 for Lewis Hamilton. That's just a tenth of a second quicker than Valtteri Bottas. Much closer than yesterday.

Image source, AP

Valtteri Bottas has switched to supersofts and his first time on that compound is a 1:24.628, around seven tenths of a second slower than Sebastian Vettel's timesheet topping time set on the ultrasofts.

Lewis Hamilton is also on a quick lap now on the supersofts. Will he maintain that sizeable gap over Bottas again?

Image source, Getty Images

Tom Clarkson
BBC Radio 5 live commentator

It is interesting to see Sebastian Vettel has come through the pits several times during this session to do practice starts. I think he has accepted he is not going to out qualifying Lewis Hamilton all things being equal.

That 1:23.989 for Sebastian Vettel is Ferrari's best time of the weekend so far, but is three tenths of a second off Lewis Hamilton's best on Friday. 

Sebastian Vettel lowers the benchmark time 1:23.989. The two Ferraris are still the only teams to go out on ultrasofts with almost half the session gone.

1) Vet 2) Rai 3) Ric 4) Sai 5) Kvy 6) Mas 7) Ver 8) Per 9) Oco 10) Str 11) Pal 12) Gio