Wasn't it The Fly - the 1986 remake of the 50s classic - that used the line; "be afraid, be very afraid"?

Well that terms would certainly apply based on this morning's evidence. Melbourne winner Nico Rosberg was quickest, a full half-a-second ahead of his Mercedes teammate, Lewis Hamilton, who was 1.3s ahead of third placed Kimi Raikkonen.

Hopefully, we don't have to read too much into it, after all, compared to the other sessions, which are all held at a later time of day (or evening) it was prett6y much redundant. On the other hand...

Much, as ever, will depend on tyres, and this weekend Ferrari and Mercedes have taken different strategic routes, the Italian team opting for mediums whilst the world champions are concentrating on sifts.

Ahead of this afternoon's session, which sees Sergio Perez back in his car after handing it to Alfonso Celis earlier, the air temperature is 21 degrees C, whilst the track temperature is 24 degrees. It is coming up to 18:00 local time and the sun is dipping below the horizon.

The good news, if you want to look it in from a 'glass half full' perspective, is that behind Raikkonen, the next twelve drivers were covered by around a second.

The tyre options this weekend are supersoft, soft and medium, as in Australia, the softest rubber making its first appearance in this session.

The lights go green and Haryanto leads the way, as Raikkonen performs a practice start. The Finn is on mediums, as are Haryanto, Nasr and Wehrlein.

Haryanto lights up the night as sparks fill the air as his Manor bottoms on the approach to T1.

As Grosjean goes quickest (35.485), the Frenchman complains that the display on his dashboard is too bright. Wehrlein goes second, ahead of Haryanto and Nasr.

A 35.314 sees Hulkenberg go top, however, he is subsequently leapfrogged by Raikkonen and then Sainz (35.132).

All eyes on Rosberg who goes quickest in the first two sectors, finally crossing the line at 32.173, 2.013s quicker than second placed Gutierrez. The German and Mexican on softs compared to the majority who are on mediums.

Ricciardo runs wide in T3 bringing out the yellows.

Verstappen posts 34.048 to go second, albeit 1.875s off Rosberg's pace. Moments later Hamilton goes second with a 32.383.

Palmer makes full use of the run-off in T15.

Vettel, getting his first taste of the softs today as Gutierrez locks up and runs wide in T1. The Ferrari driver crosses the line at 32.650, 0.477s down on Rosberg.

"This is the crucial session in terms of useful set-up work," confirms Pirelli, "as conditions are much more representative of quali and race than FP1."

Just over twenty minutes into the session Massa is the first driver to switch to the supers. He's improves from 15th (35.402) to 4th (32.873). Bottas (34.761), also on supers, improves from 11th to 4th (32.792).

More and more drivers now switching to the supers, including Ricciardo and Sainz.

Grosjean (softs) posts 33.384 to go sixth.

Unsurprisingly, on the supers, Rosberg and Hamilton trade fastest sectors. The German posts 31.001 to consolidate his top spot, Hamilton only managing 31.242.

Vettel, also on supers, fails to improve having run wide in the final corner. "I messed that one up," admits the German.

A 32.281 sees Button (softs) improve to third, just 1.280s off Rosberg's pace. Moments later Verstappen goes fourth (32.406).

Told he's done a nice job, Button replies: "I found the go faster button, I found it, I found it".

Forty-five minutes in and Raikkonen is one of the last to switch to the softest rubber. The Finn improves from 20th (35.164) to 5th (32.452).

At 'half-time', it's: Rosberg, Hamilton, Button, Verstappen, Raikkonen, Vettel, Kvyat, Bottas, Ricciardo and Massa.

Running wide, Perez fails to improves and therefore remains 15th.

As Hamilton heads out again, the cameras pick up on Ron Dennis, Eric Boullier and Fernando Alonso having a chat on the pit-wall.

Thus far, only the Manors and Saubers haven't tried the supersoft rubber.

As ever, focus now switches to Sunday, as drivers look to longer runs on high fuel.

Told to "box, box, box", Rosberg asks for one more fast lap, to check his pace on his current set of tyres. He sounds like a little kid asking to stay out and play for a bit longer.

A nice bit of pit stop practice for Vandoorne who switches from supers to softs in the process.

"Something is not right," warns Vettel, as he pulls off track. "I stop the car, I lost drive. I'll roll downhill and park between seven and eight"

The VSC is deployed.

Shortly after the VSC period ends and the all-clear is given.

Button says something about something on the track and moments later the camera picks up on some carbonfibre that has fallen from Grosjean's car after he ran wide in T13, it looks like bits of the front wing endplate.

Again, the VSC is deployed.

The debris removed, the all-clear is given. Again. Elsewhere, Vettel's car is lifted from the track its left-rear wheel askance. Mind you, the marshals making a complete pig's ear of their removal of the car doesn't help. Watching the botched recovery, Vettel pushes the wheel into place and tightens the nut.

Another radio message, not heard before, has Vettel telling his team that his left-rear is not fitted properly, that the nut is loose. "That was the problem," he confirms.

As the session comes to a close, Grosjean complains of thick smoke from the back of his car, something that Raikkonen can attest to, the Finn getting a full blast of it in his face as he runs behind the Haas.

As expected, Mercedes rules, however, the big talking points overnight will be the pace of Button's McLaren, and whether it was genuine or not, and the error that saw Vettel sidelined.

Certainly a much better session that its predecessor.

To reacp, Rosberg is quickest, ahead of Hamilton, Button, Verstappen, Raikkonen, Vettel, Kvyat, Bottas, Ricciardo and Massa.

Vandoorne is leventh, ahead of Gutierrez, Sainz, Grosjean, Perez, Magnussen, Hulkenberg, Palmer, Wehrlein, Ericsson, Nasr and Haryanto.

Check out our Friday gallery, here.