Rosberg in seventh heaven after Kvyat mayhem
Nico Rosberg sealed a perfect lights-to-flag victory to win the Russian Grand Prix for the first time and register his seventh consecutive race victory to extend his lead over team-mate Lewis Hamilton after another one-two for Mercedes.
However, it was a first-lap collision between Sebastian Vettel and Danill Kvyat that provided the major talking point from an eventful afternoon in Sochi.
Hamilton charged through the field to salvage second after starting tenth due to yet another issue in qualifying that prevented him from running in Q3, with Ferrari's Kimi Raikkonen completing the podium.
But it was the chaos at the start, caused entirely by Kvyat, that allowed Hamilton to make such swift progress, and will lead to questions of the young Russian.
Kvyat missed his braking point heading into turn two on the opening lap, ramming into the back of Vettel, who was pushed into the side of the slow-starting Daniel Ricciardo.
The contact saw Vettel suffer a left-rear puncture, with his Ferrari twitching as he went into the long turn four at full speed and he was forced to get off the throttle mid-corner, catching Kvyat out.
The Russian hit Vettel hard in the back for the second time in as many corners, but this time the force was enough to spin Vettel into the outside wall, ending his race and triggering an expletive-ridden rant from the German.
"Who the f***? Ahh, I'm out. Crashed!" an irate Vettel screamed inside his cockpit.
The safety car was needed to clear up the mess, which had also seen the Force India of Nico Hulkenberg spun out of the race by Esteban Gutierrez in the Haas, while Manor's Rio Haryanto also had to retire on the opening lap.
Once the action resumed, Rosberg immediately took control and never lost it.