Lando Norris topped the only practice session at the Sao Paulo Grand Prix as title rival Max Verstappen had a grid penalty confirmed for Sunday's race in Brazil.
Norris produced a 1:10.610s lap in the closing moments of the session to better Mercedes' George Russell by almost two tenths of a second, offering promise for the McLaren driver ahead of Sprint Qualifying later on Friday at Interlagos.
Verstappen, who leads Norris by 47 points in the Drivers' Championship with four rounds of the season remaining, aborted his only attempt at a flying lap on soft tyres and finished 15th.
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As had been expected, confirmation arrived during the session that Red Bull had installed a new engine on Verstappen's car, which will result in a five-place grid penalty on Sunday.
Oliver Bearman impressed for Haas to complete a British one-two-three, after stepping in at short notice for the unwell Kevin Magnussen, and will continue in place of the Dane for both Sprint sessions.
Norris' team-mate Oscar Piastri underlined McLaren's strength by taking fourth, but the topsy-turvy nature of the order suggested the timesheet should be viewed with some caution.
Alex Albon was fifth for Williams ahead of Ferrari duo Charles Leclerc and Carlos Sainz, who have moved the Italian squad to within 29 points of McLaren at the top of the Constructors' Championship after a win each in the last two races.
Lewis Hamilton was 16th for Mercedes after opting not to use the soft tyre at all during the session, but complained of pain as a result of severe bumping on the new track surface, an issue that troubled much of the field.
Verstappen's struggling team-mate Sergio Perez was 19th despite completing an apparent flying lap attempt on the soft tyre.
Early encouragement for Norris but mystery remains
Just five days on from a Mexico City Grand Prix which saw Verstappen given two penalties for being overly aggressive in wheel-to-wheel combat with Norris, there was great anticipation in Sao Paulo ahead of the latest chapter of what has developed into a thrilling title contest.
Norris had the early yet expected boost of Verstappen's grid penalty being confirmed, but the Brit can't be sure of it having too much impact on the Dutchman given the ease of overtaking in a quick car at Interlagos.
The early signs weren't great for Norris as he returned to the garage for a couple of significant setup changes, and then was initially off the pace of Russell on his first soft-tyre run.
However, after returning to the garage once more to make some tweaks, Norris found more than two tenths of improvement despite his tyres being on their second run.
Moments earlier, Verstappen had appeared to be on course to put himself somewhere in the top three but aborted his lap for reasons unknown.
While being fastest is encouraging for Norris, ultimately the pecking order going into Sprint Qualifying at 6pm largely remains a mystery, setting up an intriguing session at the famous circuit.
Sky Sports F1's live Sao Paulo GP schedule
Friday November 1
4.30pm: Team Principals' Press Conference
6pm: Sao Paulo GP Sprint Qualifying (qualifying starts at 6.30pm*)
Saturday November 2
1pm: Sao Paulo GP Sprint build-up
2pm: Sao Paulo GP Sprint
3.30pm: Ted's Sprint Notebook
5pm: Sao Paulo Qualifying build-up
6pm: Sao Paulo GP Qualifying
8pm: Ted's Qualifying Notebook
Sunday November 3
3.30pm: Grand Prix Sunday: Sao Paulo GP build-up
5pm: THE SAO PAULO GRAND PRIX
7pm: Chequered Flag: Sao Paulo GP reaction
8pm: Ted's Notebook
*also live on Sky Sports Main Event
Formula 1's Americas triple header concludes this weekend with the Sao Paulo Grand Prix, with every session live on Sky Sports F1. Stream every F1 race and more with a NOW Sports Month Membership - No contract, cancel anytime
(c) Sky Sports 2024: Sao Paulo GP: Lando Norris tops Practice One at Interlagos as Max Verstappen 15th following confirmation of grid penalty