Fantastic job by the Aston Martin mechanics. Lance Stroll will take part in this Q1 session - but he needs to get a move on.

The track is now in rush hour mode. Sergio Perez is searching for a bit of space. The Mexican is out of the drop zone, but he only jumps to 12th place.

16. Valtteri Bottas

17. Franco Colapinto

18. Sergio Perez

19. Liam Lawson

20. Lance Stroll

Alice Powell
British racing driver on BBC Radio 5 Sports Extra

Ferrari will be in a strong challenge to challenge for pole position. It's been the Mercedes who have topped every practice session this weekend.

George Russell, Charles Leclerc and Oscar Piastri are the top three with three minutes togo. Kevin Magnussen and Nico Hulkenberg are out of the blocks and both hit times good enough for the top 10.

Kevin Magnussen and Nico Hulkenberg are yet to put a time on the board for Haas, while Lance Stroll is still twiddling his thumbs in the Aston Martin garage.

Oscar Piastri is on a 1:33.450 and leading McLaren team-mate Lando Norris by over a tenth. Here comes Carlos Sainz, who moves up to second on the timesheets, 0.034 seconds away from Australian Piastri.

Max Verstappen lifts himself from eighth place up to fourth, which quickly becomes fifth, as George Russell knocks down Piastri with a time of 1:33.363.

Image source, Getty Images

Max Verstappen pumps in his first flying lap and leaps up the timesheets and out of the bottom five. But the Red Bull driver's marker isn't good enough to match Oscar Piastri's top time and now he's lying in eighth place.

Charles Leclerc is also safely pulled from the danger zone, with the Ferrari man sitting in third after the McLarens both improve.

16. Charles Leclerc

17. Max Verstappen

18. Kevin Magnussen

19. Nico Hulkenberg

20. Lance Stroll

Pierre Gasly, Fernando Alonso and Yuki Tsunoda are the top three so far in Q1, but here come the McLarens and the Mercedes of Lewis Hamilton.

Oscar Piastri jumps to the top of the pile with a 1:34.058 followed by Lando Norris, Lewis Hamilton has been on form in practice and on his first flyer on the softs, the seven-time world champion goes third fastest.

Rosanna Tennant
5 Live F1 reporter in Las Vegas

It's such a challenge this circuit, it's cooler than we were expecting, it's not got as much grip.

The atmosphere down here in the pit-lane and paddock is electric, everybody is gearing up for this qualifying session. We don't really know who is going to come out on top, have Mercedes sold us a bit of a red herring do you think?

We saw some questionable communication at the end of third practice when RB team-mates Liam Lawson and Yuki Tsunoda almost collided.

Pierre Gasly is one of the first drivers out on track and as the Frenchman reaches Turn Six, his face is beamed on the giant Sphere. Gasly goes quickest with a 1:34.509.

The Alpine team has a visitor - four-time major golf champion Rory McIlroy. Megastar Adele has also been spotted in the McLaren garage. Celebs galore already.

Harry Benjamin
BBC F1 Commentator

I think it's going to be a really busy qualifying session, the nature of a street track in general, trying to find that place on the circuit and coming in and out of the pits as well. It's going to be really crucial to having that communication clear between pit-wall and driver.

Q1 is green, but Lance Stroll is still in the garage. The Canadian's Aston Martin crew are desperately trying to get his car ready for this qualifying session. Will he make it?

Image source, BBC Sport

This might be a qualifying session filled with traffic chaos, a dream of a slipstream that takes one driver to glory or several cars locking up on the slippery street circuit.

If any of that happens, and you have a burning question only BBC F1 correspondent Andre Benson can answer, then send them in, day or night, using the link here

My brain still can't process the wooly hats, gloves and collective shivering in the Sin City paddock. The temperature in the desert has dropped now, so getting those softest Pirelli tyres - the C3 (white, hard), C4 (yellow, medium) and the C5 (red, soft) - in a roasty toasty working window will be crucial to qualifying success.

You may well have had a read of our F1 correspondent Andrew Benson's fascinating interview with Max Verstappen.

If not, why not?

Anyway, you can have a listen, too, now, by checking out our Chequered Flag podcast special, in which they cover an array of topics including Verstappen's driving style, a tricky season for his Red Bull team and what the future may hold.

The team also look ahead to the weekend and hear from Kevin Magnussen.

McLaren chief executive Zak Brown has been talking to BBC Sport about his team's progress and the fight for the drivers' and constructors' championships.

McLaren lead Ferrari by 36 points and Brown said "it would be unbelievable" if the team could secure their first team title since 1998.

Meanwhile, following the penalties handed to Lando Norris and then Max Verstappen at the US and Mexico City Grands Prix, Brown believes Formula 1 needs to employ full-time stewards.

He described the current rules as "overly regulated" and "overly complicated".

Have a read of the full story here.

Image source, Getty Images

The question as to whether Mercedes can carry over their practice performance into a solid qualifying showing still lingers.

Yesterday, team principal Toto Wolff played down the significance of his team setting the pace, saying they were the "low-grip champions".

"P1 is always good and then when the grip kicks in, performance deteriorates," Wolff said.

But Russell said he did not see things the same way.

"The perception of us losing performance is not quite fair," he said. "It’s more the competitors don’t use their high power and might be running a bit more fuel than us on Friday so historically they have been sandbagging a little bit more.

"There is a possibility that might happen tomorrow but the gap we have been showing has been pretty substantial and I hope we can continue that form."

Image source, Getty Images

Does last year's inaugural fight for pole in Vegas give us any clues as to what could happen this season?

Ferrari dominated qualifying in Sin City 12 months with Charles Leclerc taking the front-row spot by 0.044 seconds from team-mate Carlos Sainz. Unfortunately for Sainz, he was handed a 10-place grid penalty because the Italian team changed key parts on his car after he hit a drain cover in first practice. Harsh.

The Spaniard dropped to 12th on the grid and Max Verstappen, who was third fastest, 0.378secs away from Leclerc's pole time, moved up to second.

Lewis Hamilton and Sergio Perez were the two surprise knockouts in Q2. The Mercedes driver could manage only 11th, while Red Bull miscalculated and brought Perez in to the pits with more than two minutes still remaining in the session, resulting in him dropping down from sixth to P12.

Image source, Getty Images

The ideal scenario for Sunday's grand prix (or Saturday night in Las Vegas) is a Max Verstappen and Lando Norris slugfest from the front row two spots on the grid.

If Norris is to keep this championship scrap going to the penultimate race in Qatar next weekend, then he needs to outscore Verstappen by three points this weekend.