Sebastian Vettel once again put Ferrari at the top of the timing sheets, setting a 1:16.221s on C5 compound tyres, leaving Mercedes behind in second.
The session started and the majority of teams were able to get out on track and get some solid laps in immediately.
Haas started the session well, going fastest of all after only a few laps. It took half an hour before we first saw Red Bull leave the garage. The team managed to fix the car after Gasly had a nasty crash during yesterday’s session.
Carlos Sainz started to put some quick laps in getting lap times of low 1.17s. Vettel and Kubica seemed to focus on practising their starts. A small error from Kimi Raikkonen saw the rear end of his car spin out but there was no need to stop the session as he could continue.
It became a two horse race between Bottas and Sainz as to who will break into the 1:16s first. The Mercedes looked the best we’ve seen it so far but it was Sainz in the McLaren that broke into the 1:16s first, setting a 1:16.913s to go fastest. Bottas soon followed and set a 1:16.960s, easily the fastest time from Mercedes so far in testing.
Personal improvements continued to roll in with Ricciardo and Kvyat the next to lower their personal bests.
Bottas put in a new fastest time with just over an hour remaining in the session, a 1:16.561s on the C5 compound tyre a new best for Mercedes. Vettel improved to P3 soon after, going third fastest with a 1:16.929s on C4 tyres.
Mercedes looked as though they had indeed turned up the wick on the final day, Bottas threatening to go even faster before conveniently backing-off in the final sector several times despite setting purple sector times.
Ferrari started joining in on the games and Vettel was soon setting quick sector times before backing right off in the final sector, muddying the waters further between the two 2018 title contenders.
The timer ticked down to under an hour to go, more personal improvements continued to filter in. Raikkonen, Kvyat and Perez all improving their times leaving everyone bar Kubica in the 1:17s.
Clearly, Ferrari was keen to send a message and Vettel promptly went fastest of all, a 1:16.352s on the C5 compound. He went even quicker soon after but only just, posting a 1:16.333s.
Not content with his work up to then, he went and set the fastest time of winter testing so far and edged closer to the 1:15s. A 1:16.221s his latest benchmark.
The session due to a late red flag, Raikkonen stranded out on circuit after coming to a halt in the Alfa Romeo.
Times & lap count
Sebastian Vettel - Ferrari - 1:16.221s - 68
Valtteri Bottas - Mercedes - 1:16.561 - 70
Daniil Kvyat - Toro Rosso - 1:16.898s - 52
Carlos Sainz - McLaren - 1:16.913s - 59
Romain Grosjean - Haas - 1:17.076s - 73
Daniel Ricciardo - Renault - 1:17.114s - 51
Kimi Raikkonen - Alfa Romeo - 1:17.239s - 60
Max Verstappen - Red Bull - 1:17.709s - 29
Sergio Perez - Racing Point - 1:17.791s - 36
Robert Kubica - Williams - 1:18:993s - 47