Red Bull’s Daniel Ricciardo clocked the quickest time on the opening morning of pre-season testing at the Circuit de Barcelona-Catalunya, as McLaren hit trouble, while Toro Rosso-Honda racked up mileage.
Cool and cloudy conditions prevailed for much of the morning at the Spanish Grand Prix venue, with the four-hour session interrupted by two stoppages.
The first was caused after just half an hour by McLaren when Fernando Alonso spun into the gravel exiting the final corner, with his rear-right wheel having detached.
McLaren later confirmed that a wheel nut issue was to blame, and while Alonso returned to action shortly before lunch, he finished the morning session with just 10 laps to his name.
Meanwhile, McLaren’s former engine partner, Honda, enjoyed a productive session with new ally Toro Rosso as Brendon Hartley completed over a race distance worth of laps.
Only Renault’s Nico Hulkenberg amassed more laps than Hartley (73 to 72); the Renault driver briefly stood atop the timesheets, before being shuffled down to fourth by the time the chequered flag was waved for lunch.
Ricciardo’s pace-setting time came during the final five minutes of running as he edged in front of Mercedes’ Valtteri Bottas, recording a lap of 1:20.179.
Bottas finished 0.170s in arrears – the Mercedes driver and his Red Bull counterpart both on Mediums – while Soft-clad Kimi Raikkonen was third, 0.327s behind Ricciardo.
Hartley finished fifth for Toro Rosso, ahead of Williams’ Lance Stroll, Haas’ Romain Grosjean and the delayed Alonso.
Marcus Ericsson took ninth for Sauber, as Force India development driver Nikita Mazepin completed the order, giving the VJM11 its track debut during the opening moments of the session.
Mazepin was the culprit of the second red flag when the VJM11 came to a halt facing backwards in the Turn 4 gravel.
Lewis Hamilton (Mercedes), Sergey Sirotkin (Williams) and Carlos Sainz Jr. (Renault) will take over from their respective team-mates for the afternoon session.
| Pos | Driver | Team | Time | Gap | Tyre | Laps |
| 1 | Daniel Ricciardo | Red Bull | 1:20.179 |  |
60 | |
| 2 | Valtteri Bottas | Mercedes | 1:20.349 | 0.170 | |
58 |
| 3 | Kimi Raikkonen | Ferrari | 1:20.506 | 0.327 |  |
59 |
| 4 | Nico Hulkenberg | Renault | 1:20.547 | 0.368 | |
73 |
| 5 | Brendon Hartley | Toro Rosso | 1:22.371 | 2.192 | |
72 |
| 6 | Lance Stroll | Williams | 1:22.452 | 2.273 | |
46 |
| 7 | Romain Grosjean | Haas | 1:23.092 | 2.913 | |
32 |
| 8 | Fernando Alonso | McLaren | 1:24.202 | 4.023 |  |
10 |
| 9 | Marcus Ericsson | Sauber | 1:24.897 | 4.718 | |
41 |
| 10 | Nikita Mazepin | Force India | 1:25.628 | 5.449 | |
22 |
