Formula 2 driver Nikita Mazepin kept Mercedes well ahead of the pack as the two-day test in Barcelona concluded.
The Russian driver enjoyed his first public outing with the reigning champions having completed private runs in the 2017 car as preparation for the test.
And his performance would be impressive as he posted a 1m15.775s in the final half an hour of running, just over 0.2s slower than Valtteri Bottas’ best time on the C5 tyre from Tuesday.
Mazepin also completed the most laps for an individual driver with 128 around the Circuit de Barcelona-Catalunya.
Toro Rosso’s Alexander Albon would be second after trading best times with Ferrari Academy member Antonio Fuoco in the final hour.
The British-Thai racer would be 1.3s behind the Mercedes, however, indicating the dominance the W10 holds around the Spanish venue.
Charles Leclerc would be working with Pirelli on tyre development in his Ferrari but still posted the fourth best time on the day.
He would be followed by Kimi Raikkonen’s Alfa Romeo, which was successfully repaired in time for the track to open after the big crash for Callum Ilott on Tuesday.
Renault junior Jack Aitken was sixth fastest ahead of Kevin Magnussen in the Haas, with his best time coming on the C3 tyres.
Nick Yelloly was eighth on his second day in the Racing Point, with Nicholas Latifi ninth in the Williams having lapped half a second faster than George Russell’s best time from qualifying thanks to the C5 Pirelli compound.
Dan Ticktum’s day was disrupted by a stoppage out on track in the Red Bull during the morning, as the Briton finished 10th.
As McLaren shared their car between two development drivers, Oliver Turvey and Sergio Sette Camara, the pair finishing 11th and 13th respectively.
In between would be Lance Stroll in the Racing Point, who, like Leclerc, was running 2020 development tyres for Pirelli.
Full times from Wednesday can be seen below: