Lewis Hamilton again led a Mercedes 1-2, with title rival Sebastian Vettel a distant third, during final practice for Formula 1’s Russian Grand Prix.
Hamilton and team-mate Valtteri Bottas traded quickest times before the current points leader pulled clear with a 1:33.067, which marked the fastest ever lap of Sochi.
Bottas wound up 0.254s behind Hamilton, while Vettel was again adrift of the Mercedes duo in third position.
Vettel had a scruffy first push lap on Hypersofts and, though he improved on a later effort, he fell exactly six-tenths short, with the bulk of the time loss coming in the final sector.
Vettel finished the session walking back to his garage from the end of the pit lane after failing to get out in time before the red light came on to signal the end of proceedings, falling short by around a second.
Ferrari team-mate Kimi Raikkonen also lost substantial time through the last sector, composed of a sequence of medium-speed 90-degree turns, as he finished 0.021s back in fourth.
Red Bull pair Max Verstappen and Daniel Ricciardo, who will drop to the rear of the grid due to engine penalties, were fifth and sixth.
Charles Leclerc headed the midfield group for Sauber, holding an advantage of almost two-tenths in front of Force India’s Esteban Ocon, while Kevin Magnussen was close behind for Haas in ninth.
Sergio Perez rounded out the top 10, ahead of Renault’s Carlos Sainz Jr. and Pierre Gasly, running the older specification Honda in the Toro Rosso STR13.
Romain Grosjean, who had a late spin at Turn 17, and Nico Hulkenberg were next up for Haas and Renault respectively, with Sauber’s Marcus Ericsson 15th.
A gap of over half a second followed to Brendon Hartley in 16th place, with Williams duo Sergey Sirotkin and Lance Stroll 17th and 18th respectively.
McLaren drivers Stoffel Vandoorne and Fernando Alonso finished at the rear of the field.
Elsewhere in Formula 1 it was confirmed on Saturday that Daniil Kvyat will return to Toro Rosso in 2019.
Qualifying will begin at 15:00 local time