Ahead of Q1, the air temperature is 28.7 degrees C, while the track temperature is 32.7 degrees.

The three practice sessions have each been topped by a different driver. Verstappen leading the way in FP1, Bottas in FP2 and this morning its was Lewis Hamilton's turn.

However, FP2 was the only session to take place in conditions similar to what we can expect over the next hour and again tomorrow.

Having appeared to struggle, Ferrari took a step forward this morning, though Mercedes was keen to advise Hamilton that it was unsure of the Italian team's engine mode.

Though Bottas - winner here in 2017 - was on strong form yesterday, he was clearly struggling this morning.

That said, whatever his issue, it doesn't compare with that of Ricciardo who appeared to suffer some form of hydraulics failure late in the session. Is reliability going to spoil the Australian's final outing for Red Bull?

A number of other drivers had issues which cost them track-time, Ocon with a sensor issue, Gasly with an unspecified problem and Leclerc after an encounter with the barriers.

Late in the session, Gasly had issues of a different kind when he clashed with Grosjean, the incident now in the hands of the stewards. As is the curious case of Raikkonen, who, in a complete reversal of Hamilton's faux pas yesterday, went to enter the pitlane before changing his mind.

As ever the battle for best of the rest looks set to be fraught both today and tomorrow, with Haas, Renault, Force India, Toro Rosso and Sauber all battling away.

With the hypers fast but not at all durable, it will be interesting in Q2 to see if anyone takes the brave gamble to qualify on the ultras, though we very much doubt it.

In the moments before the green light we hear that Raikkonen has been given a reprimand for his pitlane error.

The lights go green and Hartley leads the way, followed by Leclerc, Gasly, Alonso and Ericsson.

"They are a lot hotter than they were this morning," says Gasly of his tyres.

Leclerc posts 38.968, but this is soon beaten by Gasly who stops the clock at 38.707. Hartley goes second with a 38.713.

All eyes on Raikkonen, the first of the big guns to head out. The Finn goes quickest in the first two sectors, finally crossing the line at 37.010. The quickest lap of the weekend thus far.

Moments later, Vettel responds with a 36.946, the German quickest in the first and final sectors.

Hamilton sends out a shower of sparks as he begins his first flying lap. Quickest only in the final sector - where he picks up a lot of time - he goes third with a 37.022.

Bottas posts 37.319 to go fourth, ahead of Leclerc, Ocon, Perez and Gasly.

Grosjean goes quickest in S1, as Gasly improves to sixth overall with a 37.980.

A 37.117 sees Ricciardo go fourth, while Verstappen goes fifth (37.195) and Grosjean seventh (37.575).

Moments later, Grosjean is demoted by Hulkenberg who posts an impressive 37.569.

When he asks about sector times, once again Hamilton is told that Vettel is using a different engine mode.

As if to prove the point, Vettel consolidates his top spot with a 36.775. The Mercedes pair respond, Bottas with a 36.789 and Hamilton a 36.828.

With 4:25 remaining, Magnussen, Ericsson, Vandoorne, Sirotkin and Stroll comprise the drop zone, with Alonso and the Panthers hovering.

While the top half of the timesheets seeks sanctuary in their garages, the bottom half are all on track.

Leclerc goes quickest in the first two sectors, the Sauber driver subsequently crossing the line at 37.124 to go seventh, as Ocon goes fourth with a 36.936.

No disrespect to the drivers, but the improved times are more about the cooler conditions which give better grip.

Magnussen can only manage 13th, while Perez goes ninth and Alonso, in his final qualifying session, goes 14th with a 37.890.

Having failed to make the cut, Gasly pulls to the side of the track, the Frenchman complaining of smoke from his engine.

We lose Hartley, Gasly, Vandoorne, Sirotkin and Stroll.

Quickest is Vettel, ahead of Bottas, Hamilton, Ocon, Raikkonen, Ricciardo, Leclerc, Verstappen, Perez and Hulkenberg.

Hamilton is first out, the Briton on the ultrasofts. He is followed by Bottas, Raikkonen and Ricciardo who are also on the purple-banded rubber. As are the Panthers and Vettel.

Replay shows Ricciardo almost tripping up over 2019 teammate Hulkenberg in the pitlane.

Hamilton posts a benchmark of 35.693, with Bottas posting 36.392. Raikkonen can only manage 36.735 and Ricciardo 36.964.

As Vettel posts 36.751 to go fourth, despite a couple of mistakes, Sainz goes sixth (36.982) the quickest of the hypersoft runners.

Leclerc goes seventh on the hyper, ahead of Hulkenberg and Magnussen, which means that the Panthers are going to have to make the switch to the hypers.

On the ultra, and despite a fairly clear track, Verstappen can only manage tenth (37.251).

"That was pretty s***," admits the youngster. And who are we to argue.

Guenther Steiner reveals there is an issue with Magnussen's car after the Dane ran wide and over the notorious sausage kerb..

Hamilton heads out again, this time with hypers. Vettel believes that he can improve by 0.4s on the ultras, the German having lost time behind Grosjean on his flyer.

All 15 drivers are on track with 1:4 remaining, Vettel the only driver still on the ultrasoft.

Again, Leclerc goes quickest in S1, the Monegasque possibly serving up a taster of what we can expect next year.

As he goes quickest in S2 also, Vettel is also set to improve.

Leclerc goes third and Hulkenberg fourth, ahead of Grosjean.

Ocon goes eighth and Perez fifteenth, as Vettel goes second, albeit 0.652s off the pace.

Verstappen demotes Vettel with a 36.144 while Ricciardo posts 36.964 to scrape into Q2.

"Slow down Daniel," he is told, "slow down, slow down." Does he have an issue or was that a strategic call?

Quickest is Hamilton, ahead of Verstappen, Vettel, Bottas, Leclerc, Hulkenberg, Grosjean, Raikkonen, Ocon and Ricciardo.

We lose Sainz, Ericsson, Magnussen, Perez and Alonso.

The Silvers Arrows, Ferraris and Ricciardo will all start tomorrow on the ultrasoft, while Verstappen is committed to the hypers.

"The tracks a little better for the rears," says Vettel, before adding, "do I have time for a quick pee?" Told he has four minutes, he responds: "I can make it."

Check out our Saturday gallery from Yas Marina, here.