Will there be any shock eliminations in the first part of qualifying, or will the usual cars fall at the first hurdle?

Time to find out.

Q1 is green.

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Pole position isn't a must for Kimi Antonelli in Mexico; all he has to do is keep his nose clean and finish inside the top 10 to be crowned champion. The Italian is 123 points clear of Mercedes team-mate George Russell and 124 free of Ferrari Lewis Hamilton.

Second place is still very much up grabs, with Hamilton, Max Verstappen and Charles Leclerc all chasing down Russell and separated by just nine points.

BBC Sounds

Harry Benjamin, Jennie Gow, former McLaren mechanic Marc Priestley and F1 correspondent Andrew Benson are taking us through qualifying on this Halloween night.

There are a few ways you can tune in, so either click the listen live tab at the top of the page, search for 5 Sports Extra via the BBC Sounds app or ask your smart speaker to "play 5 Sports Extra".

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If you're just joining us tonight, you may have missed the news Esteban Ocon has been replaced by Ryo Hirakawa for the Mexico City Grand Prix.

Haas haven't given any more details as to why Ocon won't be driving, but the Frenchman did have an exchange with his race engineer Laura Mueller during second practice on Friday about tyre strategy.

Hirakawa drove Ocon's car during first practice yesterday, and this will be the Japanese driver's grand prix debut.

The 32-year-old finished 19th on the timesheets earlier, just above the Cadillac of Valtteri Bottas.

Keep an eye on Max Verstappen and Liam Lawson during tonight's qualifying session, as the two drivers have both been handed a one-place grid penalty for Sunday's race for their collision during yesterday's practice session.

After Sergio Perez's car troubles in third practice, the home driver will be desperate to get out track for qualifying, as tomorrow will be his 300th grand prix start.

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Unless something disastrous happens during Kimi Antonelli's race on Sunday, reigning world champion Lando Norris will be handing over the title baton to the Italian at the chequered flag. But in third practice, the McLaren driver was able to pip the Mercedes man by the smallest of margins - 0.001 seconds to be exact.

Charles Leclerc, who was the driver to beat on Friday, was third quickest ahead of the other McLaren of Oscar Piastri and Red Bull's Max Verstappen, who had issues with his brakes late on in the session.

Lewis Hamilton, a winner here for Mercedes in 2019, was sixth, while George Russell, the man who is one point clear of Hamilton in second place in the standings, was seventh.

Verstappen's team-mate Isack Hadjar was eighth, with the two Racing Bulls of Liam Lawson and Arvid Lindblad in ninth and 10th.

Mexican driver Sergio Perez and Audi's Gabriel Bortoleto both failed to set a lap time in FP3, as engine problems limited their track running.

Lorraine McKenna
BBC Sport Journalist

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Hello again, folks. Who will take pole position for tomorrow's Mexico City Grand Prix, the second of this Americas triple-header?

We're at high altitude at the Autodromo Hermanos Rodriguez and so far, Ferrari's Charles Leclerc has been quickest in two practice sessions, with Lando Norris finishing top in the final hour earlier on.

It was close between the top teams in third practice, so this should be an intriguing fight for pole position.

Championship leader Kimi Antonelli is looking strong on the weekend he can become the new world champion with races remaining, while over at Haas, Esteban Ocon is nowhere to be seen, as the Frenchman has been replaced by Japanese reserve driver Ryo Hirakawa for the rest of the Mexican track action.

Andrew Benson
BBC F1 correspondent

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McLaren’s Lando Norris pipped Mercedes driver Kimi Antonelli to the fastest time in final practice on the weekend on which the world title is poised to change hands from the Briton to the Italian.

Norris pipped Antonelli by just 0.001 seconds at the end of the last session before qualifying as both moved ahead of Ferrari’s Charles Leclerc, who was fastest on Friday but 0.117secs off on Saturday.

Antonelli will become champion on Sunday as long as he does not lose more than 23 points to team-mate George Russell or 24 to Ferrari’s Lewis Hamilton. The only way Antonelli can be prevented from winning the title is if Russell wins and he finishes lower than ninth, or Hamilton does and he is out of the points.

McLaren’s Oscar Piastri was fourth fastest, 0.195secs off the pace, with Red Bull’s Max Verstappen 0.351secs behind Norris in fifth and ahead of Hamilton.

Russell and Red Bull’s Isack Hadjar brought up the rear of the drivers from the top four teams, with Racing Bulls’ Liam Lawson and Arvid Lindblad completing the top 10.

News before practice was that Esteban Ocon has been dropped from his Haas seat for the rest of the weekend and replaced by reserve driver Roy Hirokawa. The Japanese was 19th in final practice, fourth places and 0.577secs behind team-mate Oliver Bearman.

At the back, neither Audi’s Gabriel Bortoleto or Cadillac’s Sergio Perez set a time as they suffered engine problems that required a power-unit change.

Is Lando Norris going to make a bid for pole position for tomorrow's 71-lap grand prix in Mexico? Or is the fight between Ferrari and young title leader Kimi Antonelli?

Mercedes' Antonelli doesn't have to book a spot on the front row for Sunday's race, as he only needs a top-nine finish to secure his maiden championship. But starting on pole for your date with destiny would be nice.

Right, if you want to head out trick-or-treating so you've got some sweets in for qualifying, do it now.

We'll be back up and running from 20:45 GMT.

Q1 is going green at 21:00.

See you shortly!

Harry Benjamin, Marc Priestley and Jennie Gow are looking ahead to this weekend's Mexico City Grand Prix and Kimi Antonelli on the brink of making history as the youngest world champion in Formula 1 history.

You can listen to the Chequered Flag podcast during the break by clicking the play button above, or you can head over to BBC Sounds here

11. Nico Hulkenberg (Audi)

12. Franco Colapinto (Alpine)

13. Pierre Gasly (Alpine)

14. Fernando Alonso (Aston Martin)

15. Oliver Bearman (Haas)

16. Carlos Sainz (Williams)

17. Alex Albon (Williams)

18. Lance Stroll (Aston Martin)

19. Ryo Hirakawa (Haas)

20. Valtteri Bottas (Cadillac)

21. Gabriel Bortoleto (Audi) no time

22. Sergio Perez (Cadillac) no time

1. Lando Norris (McLaren) - 1:17.600

2. Kimi Antonelli (Mercedes) +0.001

3. Charles Leclerc (Ferrari) +0.117

4. Oscar Piastri (McLaren) +0.195

5. Max Verstappen (Red Bull) +0.351

6. Lewis Hamilton (Ferrari) +0.469

7. George Russell (Mercedes) +0.507

8. Isack Hadjar (Red Bull) +0.509

9. Liam Lawson (Racing Bulls) +0.513

10. Arvid Lindblad (Racing Bulls) +0.537

Marc Priestley
Former F1 mechanic on Radio 5 Live in Mexico City

It is super tight and I think that is the story of this weekend. We are seeing three or four teams when they get things right be potentially within a tenth or two of each other. Can't wait for qualifying.

Are McLaren also going to challenge for pole position on Saturday? Lando Norris took a dominant victory here last year on his way to his maiden world championship, and now the Briton goes quickest with a time just 0.001 second better than title leader Kimi Antonelli.

Marc Priestley
Former F1 mechanic on Radio 5 Live in Mexico City

That is a very unhappy Max Verstappen. When he says the brakes aren't working of course they do work, just not the way he would like.

Brakes are under a lot of stress here. You haven't got the normal dense air to keep those brakes cool.

Charles Leclerc is green in the opening in sector but it's the final sector where the Ferrari driver shines. He's purple at the end of the lap and goes to within 0.151 seconds of Kimi Antonelli's quickest time.

For Max Verstappen, the brakes are causing issues in the Red Bull. The Dutchman, who is aiming for a seventh consecutive podium finish this weekend, is fifth on the timesheets.

Something is not right over at Aston Martin, so Canadian Lance Stroll is back in the garage for some work on his car.

Ferrari are down in sixth and seventh as the soft running continues, Charles Leclerc quicker than team-mate Lewis Hamilton, but the pair both half a second off Kimi Antonelli's best time.

1. Kimi Antonelli (Mercedes) - 1:17.601

2. Lando Norris (McLaren) +0.166

3. Max Verstappen (Red Bull) +0.350

4. Oscar Piastri (McLaren) +0.451

5. George Russell (Mercedes) +0.506

Take two for championship leader Kimi Antonelli and this time the Italian puts down a smooth lap and leapfrogs current title holder Lando Norris by 0.272 seconds.

Four-time world champion Max Verstappen goes third quickest, more than three tenths off Antonelli, with Oscar Piastri now down to fourth.

The phone at Mercedes is ringing. It's Antonelli, and he's not happy.

"Who was the Red Bull?!" asks the 20-year-old. "Erm... that was Max," comes the reply.