Sebastian Vettel led a Ferrari one-two in opening practice for Sunday's Spanish Grand Prix.
Vettel, a four-time former champion, posted a quickest time of one minute and 23.951 seconds at the Circuit de Catalunya - comfortably faster than Nico Rosberg's pole lap last year - to top the order ahead of his team-mate Kimi Raikkonen.
Championship leader Rosberg, who is bidding to win an eighth consecutive race, was third fastest marginally quicker than his Mercedes team-mate Lewis Hamilton.
Rosberg was more than half a second adrift of Vettel, but the Ferrari drivers posted their best laps on the quicker, soft tyres, while both Rosberg and Hamilton, who trails his team-mate in the championship by 43 points, completed all their running on the slower, medium-compound tyre.
Vettel's campaign has been blighted by a number of different problems, and while he topped the order here, he ended the session being wheeled back to his garage.
The German was set to join the circuit for the closing moments, but as the lights turned to red, he was instructed to stop by his team. "It's a joke," Vettel responded over the radio.
Behind the Ferrari and Mercedes drivers was Daniel Ricciardo, who finished the 90-minute opening session 0.169 seconds faster than his new team-mate Max Verstappen.
The 18-year-old Dutchman is making his debut for Red Bull this weekend after Daniil Kvyat was demoted back to Toro Rosso following his error-strewn display at the last race in Sochi.
Kvyat, who revealed he was told he had been dropped by Red Bull while laying on his sofa in Moscow watching Game of Thrones, was 12th, and half a second slower than team-mate Carlos Sainz.
Elsewhere, Fernando Alonso was 10th in front of his home crowed while his McLaren team-mate Jenson Button was way down the order in 19th. Frenchman Esteban Ocon, replacing Jolyon Palmer for the opening practice session, was the only driver who failed to post a competitive time. Palmer will be back in the Renault for the day's second session later on Friday.
Source: PA
