Valteri Bottas led a Mercedes one-two as once again he topped the timesheets on Friday in second practice for the Russian Formula One Grand Prix.
Bottas, who had also topped the morning session, posted a best 1 minute 33.519 seconds around the 5.848-kilometre track.
His team-mate and championship leader Lewis Hamilton was second fastest, 0.267 seconds behind. The Briton improved compared to the first session which he ended in 19th after ruining his tyres with a lock-up.
Hamilton, who leads the championship 55 points ahead of Bottas, can equal Michael Schumacher's record 91 Grand Prix triumphs by winning Sunday's race.
Renault's Daniel Ricciardo had another strong session by finishing third, while McLaren duo of Carlos Sainz and Lando Norris were fourth and fifth respectively.
Red Bull's Max Verstappen had a frustrating afternoon, finishing seventh. Ferrari's Charles Leclerc was eight and team-mate Sebastian Vettel 10th, after 11th and ninth, respectievly, in the morning.
Qualifying for Sunday's race is on Saturday after final practice.
Mercedes have won all six previous races in Sochi, with Hamilton top on four occasions.