Sebastian Vettel only fifth fastest in his Ferrari as he goes into weekend in Sochi 40 points adrift of Hamilton.
Lewis Hamilton and Mercedes set the pace in Russian GP practice
Lewis Hamilton was fastest in second practice for the Russian Grand Prix as his championship rival Sebastian Vettel could finish only fifth.
Hamilton, who holds a 40-point lead over Ferrari driver Vettel with just six rounds remaining, finished 0.199 seconds clear of his Mercedes-GP teammate Valtteri Bottas at the Sochi Autodrom.
The Red Bull Racing duo of Max Verstappen and Daniel Ricciardo - both due to start Sunday's race from the back of the pack following grid penalties for exceeding the number of allocated engine parts - placed third and fourth respectively.
Vettel, who had been quickest in the opening running on Friday, was half-a-second down on Hamilton, while his Ferrari teammate Kimi Raikkonen finished sixth, one second off the pace.
Mercedes have won the previous four stagings of the race in Sochi, with Hamilton twice the victor in 2014 and 2015.
Qualifying takes place at 4pm UAE time on Saturday, with Sunday's race starting at 3.10pm.
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