Valtteri Bottas was fastest in the opening free practice session of the Formula 1 Spanish Grand Prix, with a time of 1m18.504s.
The Red Bull of Max Verstappen was second fastest, sandwiched between the two Mercedes as Lewis Hamilton wound up third, 0.123s behind his teammate.
A red flag came out midway through the session after Robert Kubica, who sat in for Kimi Raikkonen, lodged his Alfa Romeo in the gravel at the new Turn 10.
Lando Norris once again had a strong start to the weekend, as posted the fourth fastest time, 0.7s ahead of his teammate Daniel Ricciardo who was down in 14th.
Following Norris were the two Ferraris with Charles Leclerc in fifth and Carlos Sainz in sixth.
Pierre Gasly had a good run in the AlphaTauri and placed himself seventh. Behind him was the Aston Martin of Sebastian Vettel who had his best start to a weekend so far this year as he posted the eighth fastest time.
Sergio Perez had a slow session and could only manage ninth, but there is no doubt he will pick this up in the latter stages of the weekend to catch up to his teammate Verstappen.
The Aston Martin of Lance Stroll rounded out the top ten, 0.925s behind the session leader.
Yuki Tsunoda put his Alpha Tauri in 11th followed by Esteban Ocon in 12th and Antonio Giovinazzi in 13th.
Although sat at the top of the leaderboard early on in the session, Fernando Alonso was soon caught up and found himself in 15th, ahead of the two Williams of Nicholas Latifi in 16th and Roy Nissany in 17th.
Nikita Mazepin breached track limits at turn eight after a briefly trip into the gravel trap shortly after the session started.
Despite recovering from his spin, he still struggled in his Haas and ended up slowest of all.