Following overnight rain the track remained damp as this morning's session got underway in Barcelona. Aware of the limited track time they have available to them, the teams were understandably hesitant in terms of taking any risks.
That said, Esteban Ocon was first out, eventually followed by Giovinazzi, Bottas, Vettel and Latifi, all running the green-banded Inters.
While the Mercedes and Ferrari drivers were quick to get to work and begin posting times, Latifi demonstrated just how tricky the conditions were, the Canadian heading off through the gravel at Turn 12.
Opting for the cautious approach the track fell silent as the drivers waited on conditions improving, Giovinazzi finally breaking the deadlock following almost 15 minutes of total inactivity.
Seventy minutes into the session, Verstappen was the first driver to head out on slicks, the Red Bull sporting a wide aero sensor device on its side.
In the first of many such incidents over the course of the morning, Verstappen spun at slow speed in the chicane, just moments before Lando Norris went quickest on softs (22.223).
For a while the McLaren driver and Bottas traded fastest sectors, the Finn sporting the experimental hards that Pirelli is hoping to use at Zandvoort.
Unfortunately, Giovinazzi lost the rear of his car in Turn 4 and sailed across the gravel clouting the barrier with said new wing. Though he was able to continue, as he shed debris on the track while returning to the pits the session was red flagged. Though it is unclear exactly why he spun, while a toe on the wet kerbs could be the reason, it was also noted that there was a strong crosswind at that particular point.
When the session resumed the sun was just beginning to break through, and in no time at all the times were tumbling, with Magnussen, Norris and Stroll each topping the timesheets at some stage.
No sooner had Bottas gone off at Turn 5, than Verstappen went off at exactly the same spot, but while the Finn was able to continue back to his garage, the Dutchman was beached in the gravel, necessitating another red flag.
When the session resumed, Latifi did well to avoid the infamous sausage kerbs at the chicane, while Vettel went quickest with a 17.651 on the C3s, at that point the quickest time seen from Ferrari in five days of testing.
The German subsequently improved to 17.093, and while 0.025s quicker than Stroll's best, the Canadian's time was posted on the C3s while the German was on C4s.
Shortly after, Vettel followed the example of Bottas and Verstappen, getting it wrong at Turn 5, though replays showed him losing it much later in the corner.
As the four-time world champion returned to the track, dumping gravel all over the place, the red flag was waved for the third time.
When the session resumed Verstappen was first out, immediately improving to fourth with a 17.750 on hards.
Norris subsequently improved also, the Briton posting 17.573 on the mediums, and though Stroll looked set to improve also he missed out due to a slow Ocon in the final sector.
With just over 15 minutes remaining, Vettel headed out on a fresh set of C5s, we were finally about to see what the SF1000 can do.
Quickest in the two final sectors he crossed the line at 16.841, the third fastest time of testing overall but almost a second off Bottas’ best on the same compound and only marginally quicker than Kubica.
Other than Ferrari, it was a good morning for both McLaren and Racing Point, while Williams will surely take comfort from the fact that Latifi claimed third with a 17.313 that went totally unseen by the cameras.
Giovinazzi never returned to the track following his off, while Gasly, though in the upper range in terms of mileage, posted a best time 5.7s off Vettel's pace, which leads one to think that AlphaTauri is focussing on race pace.