Charles Leclerc saw off Lando Norris to finish fastest in practice for the Qatar Grand Prix.
In the sole running prior to qualifying later on Friday for Saturday’s sprint race, Leclerc ended the session 0.425 seconds clear of McLaren’s Norris.
Oscar Piastri finished third in the other McLaren as the British team bid to hold off Ferrari in the race to win the constructors’ championship.
George Russell, who claimed his third career win in Las Vegas last Saturday, was eighth, two places ahead of Mercedes team-mate Lewis Hamilton.
Newly-crowned four-time world champion Max Verstappen finished 11th, 1.2 sec off the pace.
With the drivers’ championship all over, the race for the constructors’ title takes centre stage in Doha. McLaren hold a 24-point lead over Ferrari as they look to claim their first team title in 26 years.
And although Leclerc stole an early advantage, the two teams appear evenly matched as they filled the first four places.
Yuki Tsunoda was a surprise fifth for RB, with Valtteri Bottas – a candidate for a reserve role at Mercedes next season – sixth.
Qualifying for the sprint race at the Lusail International Circuit takes place at 8:30pm (5:30pm GMT).
