Ferrari’s Charles Leclerc has posted the fastest lap ahead of teammate Sebastian Vettel in the final practice for the Formula One Mexican Grand Prix.
Lewis Hamilton came fourth as he bids to seal a sixth world title.
Leclerc posted a best 1 minute 16.145 seconds around the 4.304-kilometre Autodromo Hermanos Rodriguez in Mexico City on Saturday, with Vettel a mere 0.027 seconds behind.
Valtteri Bottas was third for Mercedes in a session that saw most drivers sit out until late rather than risk running on a damp track ahead of qualifying.
Only Bottas can prevent Hamilton wrapping up the championship in the fourth-last race of the season on Sunday.
He trails by 64 points and Hamilton will confirm victory if he earns 14 more points than Bottas this weekend.
A modest ninth-place finish at the Autodromo was enough to ensure Hamilton the 2017 trophy, and he also clinched the 2018 title in Mexico without making the podium, placing fourth.
Mercedes have recently struggled with the high altitude of the track as the low air density can affect the downforce of the car and engine performance.
Carlos Sainz of McLaren took an impressive fifth while Red Bull’s Max Verstappen, winner of the last two Mexican races, was sixth.