We're approaching the midway point of the session and a fair number of the drivers have headed in to prepare for the second part of their programme.

There is a change at the top of the pile, however, as Kimi Antonelli goes fastest with 1:20.035 on hards.

Robert: I used to think Piastri was the coolest head in F1 until I saw him pulling that silly stunt in the first bend at Austin. Unnecessary , and I hope he’s learnt from it. I still think he will win it, but it’s certainly hotting up!

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A 1:20.128 by Isack Hadjar pops him top of the order, three tenths quicker than anyone else.

Image source, Getty Images

Was a brief fluttering of those yellow flags however and normal service resumes.

Yellow flagpublished at 19:47 BST 24 October

19:47 BST 24 October

The yellow flags are being waved. Not entirely sure what for but Paul Aron is running a little slowly in the Alpine.

Andrew Benson
BBC F1 correspondent on BBC Radio 5 Sports Extra

I think I know what's happening with the Red Bull and Racing Bulls seats.

I'm pretty sure Isack Hadjar is going to get the seat alongside Max Verstappen and I'm pretty sure Arvid Lindblad, who's driving Verstappen's Red Bull in this session, will get one of the Racing Bulls seats.

The other seat is then between Tsunoda and Lawson. But it's almost like that doesn't matter, because neither of those two are going to get promoted into the main Red Bull team again, so it's like they're holding a place.

Fernando Alonso was the last driver to emerge on track but everyone is out there now.

A good time by Esteban Ocon as he dips below the 1:21s on mediums, going fastest with a 1:20.934 - six tenths quicker than Oscar Piastri.

Image source, Reuters

Duncan: Piastri has bottled it. It's between Max and Lando.

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Esteban Ocon briefly goes quickest, before Oscar Piastri improves with a 1:21.570 to retake top spot.

This circuit doesn't get much use outside of this F1 race, so there's lots of dust on the track at the moment.

That will clear as it sees more and more action.

Charles Leclerc tops the early times as he does a 1:21.939.

The fastest time from a rookie is by Pato O'Ward in Lando Norris' McLaren. He's a second off Leclerc's time.

Arvid Lindblad is in Max Verstappen's Red Bull, which is also running with some upgrades here - a bit of pressure on the 18-year-old to be giving them a bit of a testing.

Most are opting for the hard compound of tyres to start this session off.

One hour of first practice is under way.

The only team sending out their usual drivers in this session are Sauber.

Everyone else has a rookie heading out.

Paul: I believe it'll be Norris. He's shown more composure, consistancy and drive recently and I think he'll get a race or two ahead of Max (even if that happens to be via something outside of either's control (like a bad qualifying situation for Max). Oscar's head seems to be gone.

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Lewis Hamilton is having a closer look at his Ferrari as the mechanics get it ready for Antonio Fuoco to take the wheel.

A fair few significant names missing from this session then, with title rivals Lando Norris and Max Verstappen sitting this session out, as well as Lewis Hamilton and George Russell among others.

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Image source, Getty Images

Max Verstappen seemed out of the title race not that long ago but he's firmly back in the hunt for a fifth championship in a row.

"For sure, the chance is there," he said. "We just need to try and deliver these kind of weekends to the end. We will try. It is exciting.

"Of course we know we need to be perfect to the end of the season to have a chance, but we will try, and if we succeed, of course amazing.

"If we don't, we tried everything we could to the end and we kept it exciting. That's the spirit for us. It's positive pressure. It's not putting anything on us. We're not stressed about it. We're just going flat out."

Second practice: 23:00-00:00 (BBC Radio 5 Sports Extra, BBC Sounds and smart speakers)