The Sao Paulo Grand Prix is live on 5 Live and the BBC Sport websiteLewis Hamilton has been given a five-place penalty at the Sao Paulo Grand Prix for exceeding the permitted number of engine parts.
He was fastest for Mercedes in first practice, 0.367 seconds ahead of title rival Max Verstappen's Red Bull.
But the penalty is a blow to Hamilton's hopes in the championship.
Hamilton trails Verstappen by 19 points before this weekend's Brazilian race, with a maximum of 107 available over the remaining four races.
Mercedes have taken a fifth internal combustion engine at Interlagos, when only three are permitted for the season. This triggers an automatic five-place penalty.
The grid drop will apply in Sunday's Grand Prix, not the 'sprint' qualifying race that will take place on Saturday to set the grid for the main event.
This is the third and final running of the new 'sprint' format this year. Friday qualifying sets positions for the 'sprint' in Sao Paulo, which is at 19:00 GMT.
That gives Hamilton the opportunity to try to bank the three points available for victory in the 'sprint', before fighting back and trying to limit the damage Verstappen can inflict in the main grand prix.
Hamilton spent much of the only practice session before Friday's qualifying complaining about the behaviour of his Mercedes, especially that the front was bouncing.
But after trailing Verstappen on his first lap on soft tyres, Hamilton edged ahead of the Red Bull on his second and then stretched further ahead on a third lap on the same set of tyres.
Verstappen did only one flying lap on the soft tyres, so their times may not be directly comparable.
Verstappen's team-mate Sergio Perez was third fastest, ahead of Hamilton's Mercedes partner Valtteri Bottas.
Alpha Tauri's Pierre Gasly, fresh from a strong fourth place in Mexico last weekend, was fifth fastest, ahead of the Ferraris of Carlos Sainz and Charles Leclerc, and the Alpines of Esteban Ocon and Fernando Alonso, who did not use the 'soft' tyre during the session. Lance Stroll's Aston Martin completed the top 10.
McLaren's Lando Norris was 15th fastest, also having not run the soft tyres, and Williams driver George Russell was 18th.
