George Russell pipped team-mate Kimi Antonelli to the fastest time of first practice in an early show of Mercedes strength around Suzuka ahead of the Japanese Grand Prix.
Russell, who leads the championship after the season's first two races by four points from Antonelli - who won his maiden race last time out in China - clocked a best time of 1:31.666 midway through the session on soft tyres with his Italian team-mate just 0.026s adrift.
But the Silver Arrows' rivals did not finish too far behind them on the timesheet, with McLaren proving their nearest challengers in the first session.
Aiming to bounce back from the disaster that saw neither of their cars take the race start in China, the defending world champions took third with Lando Norris and fourth with Oscar Piastri - who had also failed to start the opening Grand Prix in Australia due to a crash - with both drivers finishing within 0.2s of the Mercedes'.
Ferrari, Mercedes' nearest challengers at the opening two events, were fifth and sixth fastest with Charles Leclerc and Lewis Hamilton respectively.
Max Verstappen was seventh and 0.7s slower than Russell, giving an early indication that any hope of challenging for a fifth successive Japanese GP win is likely to be a long shot for Red Bull this weekend. Isack Hadjar, who struggled for brake temperature early on, was 13th in the sister car.
Red Bull did, though, use the first session to evaluate the biggest suite of upgrades introduced to a car across the grid this weekend, with the RB22's changes including revised floor and sidepod design.
Ferrari have also brought updates to their SF-26, with revisions to its floor and front corner, whereas Mercedes and McLaren have stuck with their aerodynamic packages from Shanghai.
While the session played out in warm spring-time conditions under sunny skies, Norris, Russell and Leclerc all had off-track moments at the long, curved Spoon corner, while Williams' Alex Albon tapped the barriers when getting out of shape across the gravel at the second Degner.
Albon's Williams then sustained more substantial damage in a collision with Cadillac's Sergio Perez in the closing minutes at the final chicane.
As the Williams attempted to make a move on the brakes down the inside, the two cars made contact, scattering debris across the track.
"Oh my god!" said Perez on team radio. "I had no idea the Williams was next to us. He crashed into me."
Albon said on Williams team radio: "I don't know if he saw me."
Perez had earlier been branded an "idiot" over team radio by Russell when the Mercedes driver was caught behind the Cadillac exiting the final corner of what still proved to be the session's quickest lap.
Albon and Perez were summoned to the stewards after the session amid an investigation into the incident. Hamilton and Verstappen, along with Liam Lawson and Carlos Sainz, were also called to explain alleged incidents of blocking during the hour of running.
However, stewards took no further action regarding any of the three incidents.
Elsewhere, Racing Bulls enjoyed a productive start to the weekend with Lawson (eighth) and Arvid Lindblad (10th) finishing in the top 10, either side of Haas' Esteban Ocon in ninth.
Having delayed his arrival in Japan due to the birth of his first child, Fernando Alonso's Aston Martin was driven by reserve driver Jak Crawford in the first session. However, American Crawford was only able to complete 11 laps due to bodywork damage on the car.
Alonso, who arrived at Suzuka ahead of the opening session, returns for the second hour of running when he will that hope Aston Martin can close the 0.8s gap that they trailed Cadillac by alone at the foot of the P1 timesheet.
Friday March 27
4.30am: Team Bosses' Press Conference
5.45am: Japanese GP Practice Two (session starts at 6am)*
7.15am: The F1 Show*
Saturday March 28
2.15am: Japanese GP Practice Three (session starts at 2.30am)*
5am: Japanese GP Qualifying build-up*
6am: JAPANESE GP QUALIFYING*
8am: Ted's Qualifying Notebook*
Sunday March 29
4.30am: Japanese GP build-up - Grand Prix Sunday*
6am: THE JAPANESE GRAND PRIX*
8am: Japanese GP reaction - Chequered Flag*
9am: Ted's Notebook*
*Also live on Your Site Main Event
Formula 1 heads to the iconic Suzuka Circuit for the Japanese Grand Prix this weekend, live on Your Site F1.
