Sebastian Vettel laid down a major marker for the rest of the field on the penultimate day of pre-season testing, smashing the fastest lap in his Ferrari.
On a lengthy run using the Hypersoft tyre, the German dipped into the 1m17's on several occasions before ending with a 1m17.182s, over eight-tenths faster than Daniel Ricciardo's best from Wednesday.
The four-time world champion would follow up his qualifying-style run with a full race simulation in the afternoon and ended the day with 185 laps, not too short of three race distances.
Ferrari would be the only top team to use the softer compounds as Mercedes and Red Bull focused on long runs using the Medium and Soft rubber.
Lewis Hamilton and Valtteri Bottas were only eighth and ninth on the timesheet as a result, with Max Verstappen 12th setting the highest lap total with 187 tours of the Circuit de Barcelona-Catalunya in the RB14.
Their absence allowed the midfield teams to feature higher up with Kevin Magnussen second in the Haas with an impressive 1m18.360s on the Supersoft tyre, just 0.013s ahead of Pierre Gasly's Toro Rosso.
The two Renault drivers sat fourth and fifth with Nico Hulkenberg half a tenth clear of Carlos Sainz as one of the closest battles between teammates expected this season lived up to that expectation.
McLaren had a much better day more than doubling their lap total for this week as Stoffel Vandoorne set the sixth best time with 148 laps. It would appear not all was completely smooth, however, as the Belgian driver did lose two hours of running in the morning stuck in the garage.
Marcus Ericsson was seventh for Sauber and also just fell short of 150 laps, all five cars from Gasly in third to Ericsson would set their best on the Hypersoft tyre.
Bottas and Hamilton followed with Robert Kubica's morning run in the Williams seeing the Pole complete the top 10.
Sergio Perez would be 11th in another subdued day for Force India with Lance Stroll's afternoon outing seeing the young Canadian complete the order in 13th as 3.1 seconds (or 1.8 without Vettel) covered the field.
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