Rosberg sets the fastest lap in his penultimate loop of Sochi. Statement made.

This race will be Rosberg's then and it will be a Mercedes one two as we draw to a close.

Joe Pape: Hamilton's recovery grabs the headlines but Magnussen and Alonso have been immense for teams in dire need of a lift.

Jeremiah Kariuki: Two teams of the day - McLaren and Renault. Double points finish for MacLaren and some points for Magnussen's Renault.

Talk of Nico Rosberg taking his first ever Grand Slam today - pole, race win and fastest lap.

It's on like Donkey Kong.

ROS HAM RAI BOT MAS ALO MAG GRO PER BUT

Button would have been ahead of Sainz anyone, because of the Toro Rosso's time penalty.

But Jenson wants to be in the top 10 proper and takes advantage as Sainz locks up and goes past him in the penultimate corner.

Button could have one whole point today!

To add to what Richard says below, it was at this track in October last year where Rosberg had to retire in lap seven because of a throttle issue.

Stuff happens.

Deal with it.

Image source, Getty Images

Richard Frudd: Everyone seems to forget that last season Nico ran into problems. Fickle is pehaps the best word.

Cammy Bouse: "Conspiracy continues". Yeah, only for the loons that probably shout at the moon as well.

Bishop Yinkus: My driver of the day is Lewis Hamilton - drove phenomenal and fantastically. You can't ask for more and this is what we fans want.

Felipe Massa takes advantage of that 40-second gap on Fernando Alonso to slip on a new set of rubbers - the super softs. He is back on 20 seconds ahead of sixth-placed Alonso.

Renault could be rubbing their hands together at the prospect of their first points of the season.

Kevin Magnussen is having a good race and is up in seventh. Grosjean is a second or so behind him.

Magnussen's team-mate Palmer is 12th - his best finish was 11tth in Australia.

Image source, Getty Images

Sean Harrison: Sure I saw a shot of Rosberg sticking another pin in his Hamilton voodoo doll in his cockpit just before that water pressure issue.

Gary West: Hamilton closing, suddenly something breaks on his car. Conspiricy continues....

Rosberg has plenty of traffic in front of him, so he needs to start picking off back markers.

As it stands, his title lead will increase to 43 points.

Image source, Getty Images

The front six are spread out like nobody's business.

Hamilton has 12 seconds on Raikkonen, then the intervals are about 10 seconds, until we get to Massa and Alonso - in fifth and sixth - where the gap is 40 seconds.

Mark Gallagher
BBC Radio 5 live Formula 1 analyst

We see it time and again in motor racing - two cars identical to each other and one has more problems than the other. We used to see Mark Webber having constant problems with the KERS system on the Red Bull-Renault. It's frustrating for Lewis Hamilton but today he has driven magnificently.

Rosberg 13.4 seconds ahead of his Mercedes team-mate Hamilton now.

Better news for Lewis though.

"The situation has stabilised," says his engineer in reference to that water pressure issue.

Button is on course for at least a point by the way. He's 11th, but Sainz in front of him is due a 10-second penalty. Button is less than a second behind.

Image source, Reuters

Jennie Gow
BBC Radio 5 live pit-lane reporter

Nico Rosberg has just set the fastest lap and if he keeps that for the rest of the race it will be his first grand slam - race, pole and fastest lap.

ROS HAM RAI BOT MAS ALO MAG GRO PER SAI

Reece Young: How bad is Hamilton's luck? Driving phenomenally and another issue again.

Arabelle: Question: how often is a mechanical issue in any way a result of driving style. Hamilton's working that car hard today.

Bishop Yinkus: When is Mercedes going to get their act together on Lewis Hamilton's car? I'm sorry but why always him all the time?