Russian GP: Nico Rosberg tops Sochi's first F1 session for Mercedes

The Mercedes driver put in a time just 0.065 seconds quicker than his team-mate Lewis Hamilton.

Jenson Button impressed for McLaren, setting the third quickest time, while his team-mate Kevin Magnussen was fifth. They were split by the Ferrari of Fernando Alonso.

Drivers spent the morning session familiarising themselves with the new 3.6-mile circuit created around Sochi's Olympic Park and it was evident how little grip the new track had.

Button spun at Turn 8 unharmed, while many drivers ran wide into Turn 2.

Local hero Daniil Kvyat shone in his Toro Rosso, setting the seventh fastest time behind Force India's Sergio Perez. He was ahead of the second Ferrari of Kimi Raikkonen and his team-mate Jean-Eric Vergne.

The Red Bulls of Daniel Ricciardo and Sebastian Vettel were struggling, finishing 12th and 14th respectively, over 1.5s off the pacesetting Mercedes.

The two Williams were 10th and 11th, with Valtteri Bottas ahead of his team-mate Felipe Massa, although there was a bizarre reason why Bottas was forced to sit out much of the session after a malfunctioning tyre blanket ruined one of his sets of Pirelli tyres.

The session was held in warm and sunny conditions with a air temperature of 20 degrees C.

Aside from the regular drivers the session included Russian Sergey Sirotkin, who took over Esteban Gutierrez's Sauber, while Roberto Merhi drove Kamui Kobayashi's Caterham. The latter had a spin at towards the end of the 90-minute session when he pirouetted at Turn 15.

Only one Marussia was fielded for Max Chilton after the team's decision to not run a second car this weekend following Jules Bianchi's Suzuka accident.