Sergio Perez and Racing Point finished fastest on the second morning of Formula 1 testing in Barcelona.
As most of the teams focused on longer runs, the Mexican's 1m17.347s on the C3 tyres was enough to set the pace, albeit still four-tenths down on Lewis Hamilton's best from Wednesday.
Speaking of the world champion, he was the busiest driver in the opening four hours completing an impressive 106 laps on the board.
That figure included a race simulation which saw the Briton setting consistent lap times in the 1m20s-1m22s bracket using the C2 tyre compound.
There was also intrigue surrounding his car as Hamilton was seen operating a new technical innovation on the Mercedes, which saw the toe angle of the front tyre change when Lewis pulled the steering wheel towards him.
More details on the device, which the Brackley-based team has already said they believe is legal, will no doubt emerge.
Second fastest in the morning was Daniel Ricciardo in the Renault, four-tenths down on Perez using the same tyre.
He led his former team, Red Bull, as Alex Albon finally got his first taste of the RB16 after teammate Max Verstappen had driven both at the shakedown and on Day 1 on Wednesday.
Sister team AlphaTauri was one-hundredth slower in fourth with Pierre Gasly behind the wheel. The Frenchman though was slightly fortunate to avoid any repercussions from a spin at Turn 9 in the cold conditions in the opening minutes.
Williams' much-improved performance continued with George Russell fifth-fastest after 71 laps in the FW43.
Charles Leclerc remained in the Ferrari and also continued their subdued start to pre-season in sixth, just ahead of Hamilton in seventh.
Haas and Alfa Romeo continue to sit near the bottom of the timesheet in eighth and ninth, but it was McLaren who was slowest overall in 10th, as Lando Norris made his first appearance of pre-season.
Despite a few possible minor issues in the Renault and Red Bull garages, the incredible reliability continued with no red flags in the morning.
And once again it would be quite surprising if any team failed to join Mercedes in breaking the 100-lap mark by day's end.
Full times and lap counts from the morning can be seen below:
