Valtteri Bottas began his Mercedes career with the fastest lap at the Circuit de Catalunya, edging Ferrari’s Sebastian Vettel by two-tenths.
It was on Wednesday, Day Three in Spain, that the drivers present set their best lap times of the week.
Bottas, using Pirelli’s ultrasoft tyres, clocked a 1:19.705 which would stand as the week’s best time.
Vettel was 0.247s shy but his lap time was set on the soft tyres as was Kimi Raikkonen’s.
The Finn’s best time, set on Day Two, was a 1:20.872 with Lewis Hamilton fourth fastest for the week on the supersoft tyres.
Red Bull’s Daniel Ricciardo finished P5.
As for laps covered, Bottas was the busiest as he adjusted to life in a Mercedes and covered 324 laps.
Second busiest was Vettel with 267 laps.
It was not a great start to the pre-season for McLaren-Honda or Toro Rosso as they managed 201 and 169 laps respectively.
They were also slowest of all except for Force India development driver Alfonso Celis.
1. Valtteri Bottas Mercedes 1m19.705s 324 laps (ultrasofts)
2. Sebastian Vettel Ferrari 1m19.952s 267 laps (soft)
3. Kimi Raikkonen Ferrari 1m20.872s 234 laps (soft)
4. Lewis Hamilton Mercedes 1m20.983s 201 laps (supersoft)
5. Daniel Ricciardo Red Bull 1m21.153s 198 laps (soft)
6. Jolyon Palmer Renault 1m21.396s 174 laps (soft)
7. Max Verstappen Red Bull 1m21.769s 174 laps (soft)
8. Nico Hulkenberg Renault 1m21.791s 169 laps (soft)
9. Marcus Ericsson Sauber 1m21.824s 151 laps (supersoft)
10. Felipe Massa Williams 1m22.076s 150 laps (soft)
11. Romain Grosjean Haas 1m22.118s 143 laps (supersoft)
12. Kevin Magnussen Haas 1m22.204s 121 laps (supersoft)
13. Lance Stroll Williams 1m22.351s 120 laps (soft)
14. Antonio Giovinazzi Sauber 1m22.401s 110 laps (ultrasoft)
15. Esteban Ocon Force India 1m22.509s 107 laps (supersoft)
16. Sergio Perez Force India 1m22.534s 103 laps (supersoft)
17. Stoffel Vandoorne McLaren 1m22.576s 101 laps (ultrasoft)
18. Fernando Alonso McLaren 1m22.598s 100 laps (ultrasoft)
19. Daniil Kvyat Toro Rosso 1m22.956s 86 laps (soft)
20. Carlos Sainz Toro Rosso 1m23.540s 83 laps (medium)
21. Alfonso Celis Jr Force India 1m23.568s 71 laps (ultrasoft)