Charles Leclerc finished ahead of teammate Sebastian Vettel, with Ferrari looking set to continue their imperious form in Sochi.
The Scuderia are looking to make it four poles and four race wins in-a-row this weekend.
The Mercedes duo of Lewis Hamilton and Valtteri Bottas were close behind however, whilst Romain Grosjean was the surprise of the session, with his Haas finished sixth, splitting the Red Bulls.
No rain but drivers continue to slip
Rain had been forecast for Saturday but none came during FP3. Regardless, drivers still struggled to a stay on track.
Racing Point's Sergio Perez dangerously locked up and went off, not once but twice, at Turn 14.
Max Verstappen spun into the barriers towards the end but was able to avoid picking up any major damage.
Things were worse for home racer Daniil Kvyat, whose Toro Rosso engine broke down and will now miss qualifying.
McLaren and Mercedes reunited
The big news of the weekend dropped just before FP3 today, when McLaren announced that they would once again be powered by Mercedes engines.
The new three-year deal, which starts in 2021, will reunite the McLaren-Mercedes partnership that last raced in 2014.
The Woking-based team went from frontrunners to backmarkers when they ditched Mercedes for Honda in 2015 and although they have improved under Renault in recent times, they are still well off the pace of the big three teams.
Zak Brown, the CEO of McLaren Racing said:
"This announcement is an important message to our fans that we are committed to retuning McLaren to the front of the field."
Mercedes unquestionably provide the best engines at the moment but in two years time that could change. Renault made the bold claim that they would be challenging for the Championship in 2021, so Brown's decision may not be a sure-fire hit.
FP3 final standings:
- Charles Leclerc - 1:32.733
- Sebastian Vettel +0.316s
- Lewis Hamilton +0.396s
- Valterri Bottas +0.621s
- Max Verstappen +1.494s
- Romain Grosjean +1.575s
- Alexander Albon +1.638s
- Nico Hulkenberg +1.688s
- Lando Norris +1.794s
- Kevin Magnussen +1.813s
- Pierre Gasly +1.831s
- Daniel Ricciardo +1.853s
- Carlos Sainz Jnr. +1.874s
- Antonio Giovinazzi +2.033s
- Sergio Perez +2.127s
- Lance Stroll +2.165s
- Kimi Raikkonen +2.981s
- George Russell +3.278s
- Daniil Kvyat +3.348s
- Robert Kubica +4.209s