The session began on schedule but the pit lane remained closed as marshal crews worked to repair the fencing and tyre barriers at Parabolica. The structure was damaged after a horrific accident for Alex Pironi during the morning's Formula 3 race, after he was launched and flipped into the fencing by the sausage kerb on the outside of the circuit, Pironi was okay and walked away from the incident.
There were a flurry of cars to exit the pitlane when the light finally went green at the pit exit, giving teams only fifty minutes of dry running before this afternoon's qualifying session.
Only Ferrari and Toro Rosso opted to not join the early queue out to the track in the hope of not getting caught up in traffic, while Mercedes duo Lewis Hamilton and Valtteri Bottas focused on race starts as they left the pit lane.
McLaren's Carlos Sainz set the pace early on with a time of 1:21.736, but the two Ferrari's of Sebastian Vettel and Charles Leclerc continued the form of the weekend, Vettel setting the fastest time ahead of Leclerc.
FIA race director Michael Masi stood firm in his intentions to delete any times of drivers who run wide at Parabolica, with Haas' Romain Grosjean having to times deleted during the session for running wide, as well as Daniil Kvyat also having times deleted.
Practicing use of the slipstream was the main intentions of the two Ferrari's in the final fifteen minutes of the session, with Leclerc ahead of Vettel, Leclerc running wide in Ascari and Parabolica. Leclerc joined the list of deleted times as Haas, Mercedes and others soon joined the scarlet cars on track for the last ten minutes of running.
Renault had a positive session, with Ricciardo going ahead of the two Mercedes to take fourth position with a handful of minutes to go, while Red Bull looked to keep on the sharp end of the results, Verstappen coming within three hundredths of Vettel.