By Martin Moravec, dpa

Sochi, Russia (dpa) – Nico Rosberg maintained his 100 per cent season record with victory at the Russian Grand Prix on Sunday while Mercedes team-mate Lewis Hamilton salvaged second place and Ferrari’s Sebastian Vettel crashed out in the first lap.

Rosberg was untroubled as he made it four out of four this season and seven straight victories overall to increase his championship lead over the holder Hamilton to 43 points.

Hamilton rose from 10th on the grid to second in another damage limitation effort after a second power unit failure in a row denied him a real shot at a first season victory on the course where he had won the first two races in 2014 and 2015.

He escaped a water pressure scare to finish second ahead of Kimi Raikkonen who achieved a 700th podium finish for Ferrari; the Williams of Valtteri Bottas and Felipe Massa; and Fernando Alonso who achieved the best season result for McLaren.

Vettel’s race was over after three turns on another frustrating day for the four-time champion, hit twice from behind by the Red Bull of Daniil Kvyat, with whom he already had an altercation two weeks ago in China.

«It doesn’t help if who is behind you doesn’t brake,» Vettel said, after earlier voicing his disgust in an expletive team radio message.

Imperious Rosberg leads the championship after four of 21 races with a maximum 100 points after managing to stay out of trouble again and in part profiting from the problems of his rivals.

Hamilton has 57, Raikkonen moved into third with 43 while Vettel remained on 33 after missing out on points a second time after his engine blew up on the formation lap in Bahrain.

But Rosberg is taking nothing for granted although he delighted in «an awesome weekend; the car has been fantastic.»

«It’s four races from 21 – Lewis is going to come back. He’s on it and as motivated as ever,» Rosberg said. «Great job for Lewis to come up to second.»

Hamilton, who finished 25 seconds behind, said: «There wasn’t a doubt in my mind that I couldn’t win it, I had the pace, but then I had the problem with the engine again so I had to back off. I wasn’t at full throttle down the straights.»

Rosberg comfortably won the start while Raikkonen moved past Bottas into second and the drama soon unfolded a little further back.

Vettel was hit from behind by Kvyat’s Red Bull in the second turn, bumped into the other Red Bull of Ricciardo and suffered a flat tyre, and then spun into the safety wall after being hit once more by Kvyat while slowing down.

Vettel’s day was over while Kvyat had to settle for 15th at his Russian home race after being handed a 10-second penalty.

«I was hit twice and the second one did it. Bitter when its all over after one lap,» said Vettel, who had to start from seventh after a five-place grid penalty over a gearbox change. «The chance was there.
We had a super start.»

Kvyat later told Sky TV «I apologise to everyone who was involved,»
and his team principal Christian Horner said Kvyat went «for too much too soon.»

Force India’s Nico Hulkenberg and Rio Haryanto of Manor did also not survive the opening lap as the safety car came out to allow the debris to be cleared from the track.

By that time Hamilton had already worked his way up from 10th to fifth, was third soon after the fourth-lap restart, and moved into second after the first and only round of pit stops.

But Rosberg was coasting up front, crossing the finish line with a 25-second lead after 53 laps in Sochi’s Olympic Park in 1 hour 32 minutes 41.997 seconds to receive the trophy from Russian President Vladimir Putin.

He drew level with Michael Schumacher and Alberto Ascari with seven wins in a row while Vettel leads that list with nine straight wins.

F1 now moves to Europe for the Spanish GP in Barcelona on May 15.