Lando Norris had not been setting competitive times throughout the day, although towards the end of the afternoon session set a 1m17.709 on the C5 tyres.
The day did not come without issue however, with the new McLaren signing causing two red flags during the day after stopping on circuit both in the morning and afternoon session.
Red Bull show their hand in testing
Pierre Gasly showed Red Bull’s hand, going second fastest and setting good pace in the new Honda-powered car.
The Red Bull driver was only marginally slower than Norris, with the Frenchman using the C3 tyres to set his best time.
The times will be encouraging to Red Bull, who during the first test remained absent from setting the quickest times.
Following a difficult first test, Racing Point managed to go third fastest with Lance Stroll, using the C4 tyres on a positive day for the team.
The team had also been competitive on the C3 tyres, having been in third place for the majority of the day using the tyre compound.
Antonio Giovinazzi finished the day behind in fifth, also using the C4 tyres after setting the fastest time before the lunch break, with Toro Rosso’s Alexander Albon behind in sixth.
Charles Leclerc ended the day seventh fastest after Ferrari split their running during the day, with Leclerc taking the wheel in the morning before handing over to Sebastian Vettel in the afternoon, who went fourth quickest.
Kevin Magnussen went eight fastest in the Haas, with the Dane focusing on long runs throughout the day without showing any issues that cropped up during the first test.
Williams put in good mileage
George Russell put in a good performance in his new Williams FW42, going ninth fastest after a difficult first week of testing.
The team did not take part for two days of the first test, although managed to put some mileage on their new challenger before week one of testing ended.
However, Russell was able to put over 100 laps on the board as testing resumed in Barcelona and set competitive times on both the C3 and C5 tyres.
Mercedes and Renault off the pace
Mercedes continued to remain absent from the top of the timesheets, with Lewis Hamilton only putting his Silver Arrows 12th fastest.
Valtteri Bottas had taken over from his five-time champion team-mate in the afternoon, although running was interrupted after the Finn stopped on circuit with an oil pressure issue, resulting in a power unit change.
The issue meant Bottas could only complete a few laps towards the end of the day, going 11th fastest in the times.
Despite completing a lot of mileage, Renault didn’t challenge the best times as testing resumed in Barcelona, with Daniel Ricciardo 10th quickest and Nico Hulkenberg the slowest of anyone.