SOCHI (Russia) • Nico Rosberg became only the fourth driver in Formula One history to record seven straight wins when he cruised to victory ahead of Mercedes team-mate Lewis Hamilton in yesterday's incident-filled Russian Grand Prix.

The 30-year-old started from pole and produced an imperious performance as he pulled clear of the field to take his fourth win of the season and the 18th of his career.

He won the final three races of last year and the last time he was beaten was when triple world champion Hamilton triumphed in last year's United States Grand Prix to secure the championship.

The only three men to have reeled off seven straight wins were Italian Alberto Ascari and Germans Michael Schumacher and Sebastian Vettel, whose race yesterday was ended by a first-lap accident.

Hamilton, who started 10th, avoided the carnage of a multiple collision that eliminated Vettel to sear through the field and, briefly, threaten a challenge for the lead.

The Briton's race, however, was stymied by further mechanical problems. He suffered an engine failure in qualifying on Saturday and he was forced to nurse his Mercedes home 25 seconds behind the rampant Rosberg.

Finn Kimi Raikkonen finished third in the second Ferrari ahead of compatriot Valtteri Bottas and his Williams team-mate Felipe Massa.

Rosberg's win increased his lead in the drivers' championship to 43 points ahead of Hamilton, after four of this year's 21 races.

"Everything worked very well this weekend, thanks a lot," said the German to his team at the flag.

On a bright day on the shores of the Black Sea, the calm before the start was swiftly transformed into mayhem on the opening lap.

Rosberg made a near-perfect start, pulling clear from his 24th pole. But behind him cars collided in a dramatic incident that brought out the safety car before the race was a minute old. The chief victim of the multiple accident was the luckless Vettel, who for the second race in succession was hit by Daniil Kvyat, the Russian having collided with the German on the opening lap of the Chinese Grand Prix.

This time, Kvyat's Red Bull rammed into Vettel's Ferrari twice, the second time sending him spinning off into the barriers at Turn Two with sufficient force to wreck his car and end his race.

There was no disguising the German's anger as he delivered an expletive-strewn tirade over the Ferrari team radio while around him cars slithered and crashed amid flying debris.

After he had cooled down he said when asked about Kvyat: "I don't dislike him. I think he did a mistake two weeks ago and I think he did a mistake today... but it should not be like this. Will I speak to him? No, that is for someone else to do."

The carnage also claimed German Nico Huelkenberg of Force India and Indonesian rookie Rio Haryanto of Manor.

After racing resumed, Rosberg pulled clear again. But Hamilton, who had taken advantage of his immediate rivals' setbacks, reeled off fastest laps and trimmed Rosberg's advantage from more than 12 seconds down to eight.

Unfortunately, it was too much for his car's power unit which, having been repaired and rebuilt overnight with the inclusion of a fuel unit flown from England to Russia by private jet, showed the strain.

"We have a water pressure issue, Lewis," was the radio message after Hamilton had asked: "Are you there, Bono?" His reaction was silent, but easy to imagine.

Having fought so hard to cut Rosberg's lead to seven seconds, he slowed and allowed it to extend to 13 again before he was told that the situation "had stabilised". By then, however, with 10 laps remaining, victory was unlikely and he settled for second.

AGENCE FRANCE-PRESSE, THE GUARDIAN