Russell sets the pace in Free Practice 1 from Piastri and Leclerc for Barcelona-Catalunya Grand Prix

Mercedes driver George Russell finished fastest in Free Practice 1 for the Barcelona-Catalunya Grand Prix, beating McLaren's Oscar Piastri and Ferrari's Charles Leclerc to the top spot in Spain.

No fewer than seven rookie drivers – deemed as someone who has started no more than two Grands Prix – competed in the session at the Circuit de Barcelona-Catalunya, with F1's regulations mandating that every full-time driver must make way twice during the season.

The majority of the field headed straight out for the one-hour session at 1330 local time, but there was immediately problems for home hero Carlos Sainz.

The Spaniard was unable to restart his Williams in the pit lane, eventually being wheeled back to the garage by his mechanics before taking to the track just five minutes later.

Williams reserve driver Luke Browning was not as fortunate, the Briton forced to sit in the garage for the entire session as Alex Albon's car suffered an electrical issue before Browning even had a chance to leave the pit lane.

At the top of the leaderboard, Russell became the first driver to dip below the 1m 18s barrier on the medium Pirelli tyre, posting a 1m 17.414s as team mate and championship leader Kimi Antonelli was forced to watch on, the Italian's Mercedes being driven by Fred Vesti in FP1.

Piastri found himself only two tenths slower as Russell marginally improved, but the Australian complained that "the brakes have a vibration on them" before being told by his McLaren team the issue could only be rectified ahead of FP2.

Colton Herta, making his FP1 debut for Cadillac in place of Sergio Perez, suffered a slide through the Turn 7/8 chicane that meant he clipped the gravel on the exit.

The American was not the only driver to struggle for grip, as Vesti had a moment at Turn 1 after locking up and taking to the run-off area, Charles Leclerc ran wide at Turn 10, while Verstappen down in P6 was struggling for balance aboard his Red Bull, complaining "I don't know what to make of it to be honest".

Heading into the second half of the session, drivers moved onto the soft compound of rubber with Verstappen vaulting to the top of the times with a 1m 17.047s, just as Gabriel Bortoleto's Audi went into the gravel at Turn 7 before rejoining and stating "the car is unstable".

Minutes later, Russell drastically improved the best time in the session with a 1m 16.363s, as Piastri again dropped into P2 with Leclerc P3, the order remaining unchanged at the chequered flag.

Verstappen was fourth fastest from reigning Formula 2 champion Leonardo Fornaroli (driving Lando Norris' McLaren) and Paul Aron (driving Nico Hulkenberg's Audi). The top 10 was completed by Liam Lawson's Racing Bulls, Dino Beganovic (driving Lewis Hamilton's Ferrari), the second Racing Bulls car of Arvid Lindblad and Franco Colapinto's Alpine.

Ollie Bearman's Haas was P11 and headed Bortoleto, Sainz, Ayumu Iwasa (driving Isack Haadjar's Red Bull), Vesti, Esteban Ocon's Haas and Pierre Gasly, who complained of a late issue with his Alpine.

Valtteri Bottas (Cadillac) was P18 from both Aston Martins of Fernando Alonso and Lance Stroll, with Herta and Browning completing the order ahead of Free Practice 2 on Friday afternoon.