Sebastian Vettel topped the timesheets for Ferrari on the penultimate morning of pre-season testing on Thursday.

Overnight rain left the Barcelona track wet for the first two hours, giving teams a first opportunity to run their 2020 cars on the intermediate tyres.

Eventually, the slicks would return, and Vettel went fastest initially on the C4 compound before improving by two-tenths on the C5 tyre with a 1m16.841s on Pirelli's softest rubber.

Though that time might be over a second off Valtteri Bottas' best on the same tyre from last week, the track had lost most of its grip after being washed and it also seems Ferrari is still running a very conservative engine map based on speed trap data.

As the track dried a number of drivers had excursions off track, Antonio Giovinazzi had the biggest crash in the Alfa Romeo at Turn 4, causing a red flag.

Vettel, Valtteri Bottas, Max Verstappen also spun off at Turn 5, with the Dutchman getting beached in the gravel and needing to be recovered.

Still, enjoying the changing conditions was Lance Stroll as he put Racing Point second just three-tenths behind Vettel on the C3 tyres.

Nicholas Latifi put Williams into third with a late lap before lunch, bumping Lando Norris down to fourth in the McLaren, though his 1m17.5s on C2 tyres was an impressive time.

Indeed, Verstappen was two-tenths slower than the Briton on the same tyre in fifth, with a modest 28 laps having opted not to run in the wet.

Mercedes' low-key start to the second week continued with Bottas in sixth, ahead of Esteban Ocon in seventh for Renault.

Kevin Magnussen was eighth ahead of the garage-bound Giovinazzi after his crash, with Pierre Gasly rounding out the morning runners.

Full times and lap counts from Thursday's first four hours of running can be seen below: