World champion Lewis Hamilton fought back to top the times again ahead of his Mercedes team-mate Nico Rosberg in Saturday morningâ€™s third and final free practice for Sundayâ€™s Russian Grand Prix.
The 31-year-old Briton, who trails his German team-mate by 36 points in this yearâ€™s driversâ€™ title race after just three events, clocked a best lap time of one minute and 36.403 seconds in the final minute of a busy session run in cool conditions at the Sochi Autodrom.
Minutes earlier, Rosberg had led the times by half a second and retired to his garage, leaving a determined Hamilton to respond again with an aggressive sliding demonstration of his talent.
It was enough for the defending three-time champion to outpace Rosberg by 0.068 seconds ahead of the two Ferraris led by four-time champion Sebastian Vettel, but proved also that he was pushing to the limits to extract his speed from the car.
Rosberg was fastest in Friday morningâ€™s first session before Hamilton took over at the top in the second session.
German Vettel was six-tenths of a second off the pace set by Hamilton with his team-mate Finn Kimi Raikkonen 1.3 seconds adrift of the leading Mercedes.
That suggested qualifying later on Saturday was likely to be decided by a fine margin between the two Mercedes men.
Brazilian Felipe Massa was fifth in the leading Williams ahead of his team-mate Finn Valtteri Bottas, Dutch teenager Jos Verstappen of Toro Rosso and 2009 champion Briton Jenson Button of McLaren Honda.
Spaniard Carlos Sainz was ninth in the second Toro Rosso and Mexican Sergio Perez 10th for Force India, leaving a disappointed Australian Daniel Ricciardo down in 10th in his Red Bull.
His team-mate local hero Russian Daniil Kvyat was 13th behind two-time champion Spaniard Fernando Alonso in the second McLaren, an endorsement of his teamâ€™s improvement since their disappointing season in 2015.