Nico Rosberg delivers another perfect drive to win in Russia

Lewis Hamilton finished a superb second having started 10th on the grid, the reigning champion's excellent start helped by a safety car following Sebastian Vettel's first lap exit.

Vettel's Ferrari team-mate Kimi Raikkonen was third, with Williams duo Valtteri Bottas and Felipe Massa fourth and fifth respectively.

Rosberg has now won all four races this season, as well as the last three races of last season. Only Michael Schumacher in 2004 and Alberto Ascari from 1952-53 have matched that achievement, while Vettel is the only man to have more back-to-back wins with his nine consecutive wins in 2013.

"Excellent job Nico! Well done! Top job!" came the message from the Mercedes pits to Rosberg via the put radio as he crossed the line.

"Thank you. Everything worked really really well this weekend. Well done everybody," replied the driver.

"It's been a great weekend," smiled Rosberg on the podium afterwards.

"Great job from Lewis to come up so quickly from second to tenth," he added, when asked about how he'd had to keep his pace up with repeated fastest-laps while being pressured by his team-mate."

Hamilton then explained that he had a water pressure issue which stopped him trying to close the gap, and was clearly disappointed at the after-race ceremony as he gave away his champagne without even popping the cork.

Vettel's exit will be chewed over after the race in some detail: having come together with Dani Kvyat in the last race in Shanghai, the Kvyat seemed to rear-end Vettel twice in the opening few corners - the second of which sent the German spinning into a side wall.

While Vettel's poor luck in 2016 continued, Hamilton's improved slightly. His Mercedes team flew a new fuel system out (via private jet!) to fit to his car on Sunday morning following his ERS failure in qualifying for the second race running.

It seemed to fix his issues as he closed to within 10 seconds of Rosberg before Hamilton was struck by the new problem - and the Englishman ended up almost 30 seconds behind his team-mate at the chequered flag.

Furthermore, he will now be 43 points behind in the drivers' standings, with 57 to Rosberg's 100. With the way the season going, it's hard to see how Hamilton will close the gap - even if the reliability issues that have dogged his season are solved between now and the next race in Barcelona.

Nico Rosberg started on pole and got a fine start at the Russian Grand Prix, never putting a tyre wrong throughout.

Rosberg led in to Turn 2 - the first braking point on the circuit - but further behind him Vettel was hit by Daniil Kvyat, causing the Ferrari to hit Daniel Ricciardo. Then going through Turn 3, Vettel lifted off and was hit by Kvyat again, sending the German in to the barriers and out of the race.

Lewis Hamilton managed to avoid the incident to emerge in fifth place behind Rosberg, Kimi Raikkonen, Valtteri Bottas and Felipe Massa, and the defending champion recovered to second place from tenth on the grid despite more reliability concerns.

Rosberg was able to pull a comfortable lead as Hamilton fought his way in to second, with the gap at 13 seconds after the pit stops. With a one-stop strategy the preferred choice, Hamilton was closing the gap on track and had managed to reduce it to 7.7s when a water pressure problem forced him to back off.

Hamilton eventually crossed the line 25 seconds adrift of Rosberg - who extends his championship lead to 43 points - but had enough in hand over Raikkonen in third place.

Bottas came home fourth ahead of Massa, with the second Williams having enough of a buffer over Fernando Alonso to even make a second pit stop. Alonso had made an excellent start to run in the top ten and avoid the early contact, but he was a lap down such was Mercedes' advantage this weekend.

Kevin Magnussen scored Renault's first points of the season in seventh place, with Romain Grosjean finishing eighth for Haas ahead of Sergio Perez and Jenson Button.