Piastri has not won since the Dutch Grand Prix
McLaren's Oscar Piastri outpaced title rival and team-mate Lando Norris in practice at the Qatar Grand Prix.
The Australian, who trails Norris by 24 points in the championship with two races to go, edged the Briton by 0.058 seconds in the only session before sprint qualifying, which starts at 17:30 GMT.
Norris, who will win the championship on Sunday if he outscores both Piastri and Red Bull's Max Verstappen by two points over the weekend, was on a faster lap but ran wide out of the final corner.
Verstappen was down in sixth place, 0.580secs off the pace after complaining of a number of problems with his car through the session.
