Sainz's 1m31.247s set on the C3 tyres headed the times by 0.236s from Sergio Perez in the Red Bull, who also set his best time on the C3 compound, on another stalled morning of testing.

The final day of testing was halted after only 27 minutes when a drain cover came loose on the outside kerb approaching Turn 11 – the same spot where another drain was dislodged and disrupted running on Thursday.

It appeared Red Bull's Perez ran over the broken drain cover but avoided major car damage, and the session was stopped for 1h17m in total for repairs and checks across the rest of the track.

As a result, the planned one-hour lunch break was cancelled to give back running time, with action set to continue non-stop until 7pm local time (4pm GMT).

After the delay, the majority of teams were able to enjoy interrupted running, but McLaren was limited to just 20 laps with Lando Norris due to a suspected clutch problem.

Elsewhere, Valtteri Bottas was restricted to 28 laps for Sauber with the team garage screens up for a lengthy period as the team worked on the floor and rear end of the car.

Behind timesheet toppers Ferrari's Sainz and Red Bull's Perez, Lewis Hamilton took third for Mercedes with a best lap of 1m31.999s set on the C5 compounds, but his morning was notable for numerous lock-ups and sliding around in the W15.

Aston Martin's Lance Stroll took fourth on the times ahead of Norris, with Alex Albon taking sixth for Williams with his best time set on the C3 tyres despite briefly switching to the softer compounds later in the session.

Kevin Magnussen led the lap tally with 78 for Haas this morning, taking seventh overall on the times, ahead of Alpine's Esteban Ocon and Bottas.

Daniel Ricciardo rounded out the times having stuck to the hard C1 compound for the majority of the morning to focus on race runs, putting in 70 laps for RB, and as a result was 5.7s off the outright pace.

F1 pre-season testing concludes today with running ending at 7pm local time (4pm GMT).

Results at 2pm