Russian F1 GP: Lewis Hamilton concerned by Nico Rosberg's failure

Hamilton beat Ferrari's Sebastian Vettel to victory, racing alone out front after the other Mercedes of Rosberg retired with a throttle pedal damper problem having led the early laps.

Hamilton also had to manage an unidentified rear wing issue in the closing stages of the race, which resulted in his team telling him not to use DRS.

"I don't know what was wrong with my car, I don't think it was DRS, but it was something happening to the rear end, that's why my pace decreased," he said.

"The reliability is something we have focused on a huge amount over the last year and a half and for whatever reason, we are struggling and having a few problems with it.

"Nico has been incredibly unfortunate to suffer the worst.

"We will be working as hard as we can to rectify it - and hope in the next races we don't have a problem - but of course it is a concern for us."

Hamilton added it was disappointing that he did not get the chance to fight with Rosberg on track.

"Nico was holding his ground and it looked like we were going to have a race," he said.

"I was thinking 'this is great', but then he went a bit wide and I overtook him - maybe before or after that he started to have problems.

"It's unfortunate for the team - it was a good opportunity to get the constructors' championship this weekend."

Rosberg's throttle problem meant his car's accelerator was sticking, leaving him with no choice but to retire.

"It's unbelievable something like this had to happen," said the German, whose world championship hopes were dealt a serious blow.

"At the moment I'm disappointed with today and I don't think about the rest.

"But I never write anything off, and picking myself up is not a problem either."