Nico Rosberg led from the start as he recorded his seventh successive Formula One victory at the Russian Grand Prix on Sunday.

World championship leader Rosberg was in charge throughout and never came under serious pressure from the remainder of the field, making it four wins from four this season.

The German's quick start saw his Mercedes get clear of the drama that ensued behind him on the opening lap, with the safety car quickly deployed.

After Daniil Kvyat's aggressive driving irked Sebastian Vettel last time out in China, the Russian provoked a similar reaction when he made contact with the rear of the Ferrari twice on the opening lap to send the German careening into the wall.

One of the beneficiaries of the contact was defending champion Lewis Hamilton, whose luck turned after electrical issues in qualifying forced him to start from 10th.

Hamilton showed great composure to work his way up to second, but he was unable to stop Rosberg from finishing at the top of the podium for a second straight year at Sochi, with the surviving Ferrari of Kimi Raikkonen rounding off the top three.