Red Bull's Max Verstappen set the fastest pace in Friday practice at the Mexico City Grand Prix as Red Bull once again made their intentions known in the race
Verstappen was 0.424 seconds quicker than Mercedes' Valtteri Bottas, with his title rival Lewis Hamilton 0.509secs off the pace.
Red Bull's Sergio Perez was fourth quickest, ahead of Ferrari's Carlos Sainz and Alpha Tauri's Pierre Gasly.Ferrari's Charles Leclerc was seventh, ahead of Alpha Tauri's Yuki Tsunoda, Aston Martin's Sebastian Vettel and Alpine's Fernando Alonso.
The day's running produced the expected picture at the front - Verstappen a strong favourite for race victory and Hamilton and Mercedes facing a race of damage limitation.
Hamilton, who was reprimanded by stewards in the lunch break for not re-entering the track correctly in the first session after running through the grass, also ran off track at the same point on his first stint of the afternoon, damaging his tyres.
He quickly worked his way back up the timesheet after that but, although he was initially able to trade quickest laps with Verstappen, the Red Bull ultimately had too much pace on the soft-tyre qualifying simulations.
This is the first of five races in six weekends that will bring the F1 season to a close.
Verstappen said: "It was quite a good day. Always trying to improve the car. It seemed like the car is working quite well. A few things to look at, but pretty good. It's a positive start to the weekend."
Hamilton said: "The car has been feeling OK. We have not had any major issues. We are giving it absolutely everything we've got and they are just quicker than us at the moment.
"I have no real concerns. Just chipping away at the set-up and trying to improve it. We are lacking downforce, which is probably why we have the half-second difference to us."