Nico Rosberg topped the opening session of the Russian Grand Prix as Mercedes dominated FP1.
Rosberg enters the Sochi weekend with a 36-point championship lead and six straight wins under his belt and topped teammate Lewis Hamilton by 0.722s. However, it seemed Hamilton was unable to hook up a clean lap after struggling with the lack of grip at the Sochi Autodrom. The nearest Ferrari was Sebastian Vettel, one second off Rosberg's benchmark, but the Italian team did not use the faster super-soft tyres during the 90-minute session. Ferrari is set for an engine upgrade this weekend which it hopes will provide more power on Sochi's long straights.
The morning session began with the debut of Red Bull's Aeroscreen canopy design, which was trialled for an installation lap on the car of Daniel Ricciardo. The Australian completed a lap which will allow him to give feedback on visibility from within a cockpit. The device is one of two concepts currently being considered for implementation in 2017 to protect drivers from flying pieces of debris and tyres.
The low grip at the Sochi Autodrom was a clear problem with numerous drivers spinning off the race track. Lewis Hamilton had two spins at Turn 2, while Jenson Button and Sebastian Vettel both lost the rear end coming through Turn 15. Vettel also lost the rear at the apex of Turn 17 later in the session, a spin replicated by Red Bull's Daniil Kvyat in the closing half hour. In the closing stages Turn 2 once again caught out Hamilton, Nico Rosberg, Marcus Ericsson and Jolyon Palmer.
Raikkonen finished fourth using the soft tyres 0.033s ahead of the Williams of Felipe Massa on the super-softs. Ricciardo finished fifth for Red Bull, 1.5s off the lead, ahead of Valtteri Bottas and Red Bull teammate Kvyat. Sergio Perez and Carlos Sainz rounded off the top ten.
McLaren drivers Jenson Button and Fernando Alonso finished 10th and 11th as the team hopes to make more progress this weekend. Russian driver Sergey Sirotkin, filling in for Kevin Magnussen, finished 13th in his first appearance for Renault ahead of Sauber's Felipe Nasr, who has a new chassis this weekend. Max Verstappen ended the morning 15th ahead of Haas pairing Esteban Gutierrez and Romain Grosjean.
Renault's Jolyon Palmer could only manage 18th and spun in the final sector after the chequered flag. Sauber's Marcus Ericsson finished ahead of Manor pairing Pascal Wehrlein and Rio Haryanto. Force India test driver Alfonso Celis, replacing Nico Hulkenberg for FP1, finished last, eight tenths off Haryanto's soft tyre time despite setting his quickest on the super-soft compound.