George Russell went fastest ahead of teammate Kimi Antonelli in an eventful first practice for the Japanese Grand Prix on Friday as Mercedes continued their dominant start to the Formula One season.
Mercedes have claimed one-two finishes at both grands prix so far and they were again out in front in dry, sunny conditions at Suzuka.
Early championship leader Russell clocked a fastest lap of 1min 31.666sec to pip 19-year-old Antonelli, who won the first grand prix of his career in China two weeks ago, by 0.026sec.
World champion Lando Norris was third, followed by his McLaren teammate Oscar Piastri, and Ferrari pair Charles Leclerc and Lewis Hamilton.
Red Bull's four-time world champion Max Verstappen was seventh, 0.791sec off Russell.
Norris, who along with Piastri did not start the Chinese Grand Prix because of a technical issue with his car, came out early but was then grounded for the first half of the session.
Alex Albon lost the nose of his Williams after crashing into Cadillac's Sergio Perez late in the session.
Albon had earlier skidded off the track and driven deep into the gravel before clipping a barrier on his way back.
Verstappen had a wobble when he tried to accelerate out of a corner.
His Red Bull teammate Isack Hadjar also struggled, telling his team early in the session that his car was "pulling".
Aston Martin replaced Fernando Alonso with reserve driver Jak Crawford for the session.
Alonso arrived in Japan late following the birth of his first child.