Renault’s Nico Hulkenberg set the fastest time of the week as Formula 1’s opening pre-season test concluded in Spain on Thursday.
Hulkenberg moved to the front of the field with a time of 1:17.393 – achieved on Pirelli’s C5 tyres – during the afternoon session, before stopping on track shortly after.
Renault is still investigating the cause of Hulkenberg’s stoppage, which restricted the German to just 24 laps through the course of the four-hour session.
Morning pacesetter Alexander Albon was demoted to second by Hulkenberg’s improvement but nonetheless capped an encouraging week for Toro Rosso by completing 134 laps, his best time within three-tenths of Hulkenberg's effort.
Hulkenberg’s Renault team-mate Daniel Ricciardo carried out running in the morning session and placed third, ahead of Mercedes pair Valtteri Bottas and Lewis Hamilton, who were the only other drivers to break into the 1:17s.
Ferrari’s Charles Leclerc had a moment through Turn 5’s gravel and had a couple of sensors work their way free from his car, but he swiftly returned to action and placed sixth, within a tenth of Hamilton.
Lando Norris caused an early red flag when he went off into the Turn 5 gravel at slow speed while eighth-placed Antonio Giovinazzi halted at the pit exit during the closing stages.
Giovinazzi re-appeared but halted again just a few minutes later, with that stoppage bringing a slightly premature end to proceedings.
The Italian was nonetheless the most productive individual through Thursday’s running, racking up 154 laps in Alfa Romeo’s C38.
Haas duo Romain Grosjean and Kevin Magnussen rounded out the top 10 for Haas, in front of Red Bull’s Pierre Gasly and Racing Point’s Lance Stroll.
Williams pair George Russell and Robert Kubica finished comfortably adrift of the pack as they put the FW42 through its early paces, completing most runs with aero fences attached to the car.
Russell was seven-tenths behind ex-Williams racer Stroll, with morning driver Kubica another half a second down on his team-mate.
Formula 1’s second pre-season test will begin at the Circuit de Barcelona-Catalunya at 09:00 on Tuesday.
| Pos | Driver | Team | Time | Gap | Laps | Tyres |
| 1 |  Nico Hulkenberg |
Renault | 1:17.393 | 24 | C5 | |
| 2 |  Alexander Albon |
Toro Rosso | 1:17.637 | 0.244 | 136 | C5 |
| 3 |  Daniel Ricciardo |
Renault | 1:17.785 | 0.392 | 34 | C5 |
| 4 |  Valtteri Bottas |
Mercedes | 1:17.857 | 0.464 | 57 | C5 |
| 5 |  Lewis Hamilton |
Mercedes | 1:17.977 | 0.584 | 58 | C4 |
| 6 |  Charles Leclerc |
Ferrari | 1:18.046 | 0.653 | 138 | C3 |
| 7 | Lando Norris |
McLaren | 1:18.431 | 1.038 | 132 | C4 |
| 8 |  Antonio Giovinazzi |
Alfa Romeo | 1:18.511 | 1.118 | 154 | C3 |
| 9 |  Romain Grosjean |
Haas | 1:18.563 | 1.170 | 64 | C3 |
| 10 |  Kevin Magnussen |
Haas | 1:18.720 | 1.327 | 65 | C3 |
| 11 | Pierre Gasly |
Red Bull | 1:18.780 | 1.387 | 146 | C3 |
| 12 |  Lance Stroll |
Racing Point | 1:19.664 | 2.271 | 72 | C2 |
| 13 | George Russell |
Williams | 1:20.997 | 3.604 | 17 | C3 |
| 14 |  Robert Kubica |
Williams | 1:21.542 | 4.149 | 48 | C2 |
