Nico Rosberg topped the times ahead of championship leader and Mercedes team-mate Lewis Hamilton in Friday's sun-swept opening free practice for Sunday's inaugural Russian Grand Prix.
Five days after Jules Bianchi's devastating accident brought the rain-lashed Japanese Grand Prix to a premature end, the paddock and pit-lane were glad to focus their attention on learning their way around the new Olympic Park circuit and expressing their support for the 25-year-old Frenchman on the track.
The Marussia team ran only one car in a demonstration of their support for the absent Bianchi, who was severely-injured in last Sunday's Japanese race and remained in intensive care in hospital in Japan, as the action began. (Formula One Debates Risks After a Driver is Badly Hurt)
The team had prepared a second car and nominated reserve driver American Alex Rossi, but on Friday morning decided to run only Briton Max Chilton, leaving Bianchi's car in their garage.
On a morning of increasingly warm sunshine at the Black Sea resort circuit, Briton Jenson Button demonstrated the potential of his McLaren with some early fastest laps before the Mercedes men rose to the top.
German Rosberg, who trails Hamilton by 10 points in the title race with four races remaining, ended up fastest with a best lap time of one minute and 42.311 seconds, just 0.065 seconds faster than his British team-mate.
Button, the 2009 champion, finished third, two tenths behind the championship rivals, ahead of two-time champion Spaniard Fernando Alonso of Ferrari, Danish rookie Kevin Magnussen in the second McLaren and Mexican Sergio Perez of Force India.
Russian Daniil Kvyat, celebrating his prospective switch from Toro Rosso to Red Bull next year by racing on home soil in Russia's maiden F1 race, was seventh ahead of Finn Kimi Raikkonen in the second Ferrari, Frenchman Jean-Eric Vergne in the second Toro Rosso and Finn Valtteri Bottas of Williams.
Defending four time champion German Sebastian Vettel, who last weekend announced his departure from Red Bull in 2015, was 14th, two places behind his team-mate Australian Daniel Ricciardo.