Valtteri Bottas was in 'marathon man' mode on Wednesday, finishing fastest and clocking in with a massive 143 laps under his belt.
The Finn just tore relentlessly through Mercedes' tyre and aero data programme as the German squad sought to get on top of its recent degradation and balance struggles.
Bottas edged out Sebastian Vettel, at least in terms of lap times as the Ferrari driver racked in just 63 laps following a hydraulic leak in the morning and a data acquisition issue in the afternoon which limited the Scuderia's track time.
Toro Rosso's Carlos Sainz took over from Dany Kvyat and secured third fastest, but the happiest man in the paddock was undoubtedly Stoffel Vandoorne who was spared any drama and finally succeeded in putting his McLaren through its paces.
Team boss Eric Boullier even labeled the trouble-free session the best test day McLaren has enjoyed since the beginning of the year!
Renault's Sergey Sirotkin was another long distance runner on Wednesday, accumulating 123 laps and ending the day 9th fastest, just ahead of Sauber's Pascal Wehrlein and Force India's Sergio Perez.
GALLERY: All the action from the Day 2 in-season testing at Bahrain
Keep up to date with all the F1 news via Facebook and Twitter
Lando Norris has taken a step back from his furious post-race reaction to Franco Colapinto’s…
Lando Norris’ call for Franco Colapinto to be handed a race ban after the chaos…
On this day in 1980, Williams' Alan Jones clinched his sole F1 world championship with…
Red Bull missed out on its first victory of the 2026 season by the narrowest…
Last weekend’s Azerbaijan Grand Prix claimed plenty of victims, but for Liam Lawson, the most…
Charles Leclerc left Baku with a result that flattered Ferrari’s pace – and a warning…