Russell on top in disrupted final morning session in Barcelona

George Russell put Mercedes on top in the final session of dry running in Barcelona on Friday, but the morning was marred by no less than five red flags.

The Briton nevertheless gets bragging rights for outpacing Red Bull's Max Verstappen by over half a second and Aston Martin's Sebastian Vettel.

However, Russell's best lap of 1m19.233s was set on Pirelli's C5 ultra-soft tyre, while Verstappen relied on the mid-range C3 to set his quickest time.

Barcelona Pre-Season Test - Day 3

Fernando Alonso triggered the first red flag of the day when his Alpine suffered a hydraulics issue according to the Enstone squad that brought the Spaniard's day to a premature end after just 12 laps.

Unfortunately, the problem will prevent Alpine from running in this afternoon's wet weather session.

In the latter part of the morning, an off-track excursion and crash by AlpahTauri's Pierre Gasly at Barcelona's middle sector Turn 5 led to a second neutralization of the session.

The action resumed with an hour to go on the clock only for Alfa Romeo's Guanyu Zhou to bring out the third red flag of the day, the F1 rookie suffering on off at Turn 10 in the final sector.

But that wasn't the last of Alfa's issues, with the Chinese charger stopping in the first sector and triggering a fourth red flag.

Finally, the fifth halt came courtesy of Sebastian Vettel, whose Aston Martin was seen smoking and stranded in the closing stages of the session.

While Russell led the lap count with 66 laps, Haas was once again at the other end of the spectrum, with a suspected oil leak limiting Nikita Mazepin's running to just 9 laps.

Keep up to date with all the F1 news via Facebook and Twitter