Lando Norris set the fastest time on Wednesday at the Circuit de Barcelona-Cataluyna as F1 pre-season testing began.
Reading too much into the results of pre-season testing, especially on day one, is not often the wisest of moves but it is likely spirits will be particularly high in the McLaren and Ferrari garages after the first day of running.
Charles Leclerc topped the morning session before handing over to team-mate Carlos Sainz in the afternoon and both remained inside the top three by the time the chequered flag fell on the day.
It was Lando Norris, however, that will leave the Spanish venue the largest spring in his step after comfortably topping the order, even before a late glory run lowered his time further to a one minute 19.568secs.
Mercedes will be content with its work with Russell fourth, Hamilton fifth and with 122 laps completed between the two drivers.
Max Verstappen was one of a handful of drivers to feature in both the morning and afternoon sessions, completing a staggering 147 although his one minute 22.246s was only the eighth-best.
It was a difficult day for Haas with problems for both Nikita Mazepin and Mick Schumacher.
For Mazepin, a cooling leak limited him to 20 laps, whilst Schumacher fared little better after returning to the garage with a damaged floor.
Robert Kubica suffered an equally trying morning and completed just nine laps for Alfa Romeo.
F1 WEDNESDAY RESULTS
1. Norris 1:19.568 
2. Leclerc 1:20.165 
3. Sainz 1:20.416 
4. Russell 1:20.784 
5. Hamilton 1:20.929 
6. Vettel 1:21.276 
7. Tsunoda 1:21.638 
8. Alonso 1:21.746 
9. Verstappen 1:22.246 
10. Bottas 1:22.572 
11. Albon 1:22.760 
12. Schumacher 1:22.962 
13. Stroll 1:23.327 
14. Latifi 1:23.379 
15. Mazepin 1:24.505 
16. Kubica 1:25.909 [nine]