Nico Rosberg responds to pressure from Lewis Hamilton to extend his lead over Lewis Hamilton to one second. Felipe Massa, meanwhile, is 3.9 seconds further back, 0.8 ahead of Williams team-mate Valtteri Bottas.

Image source, Reuters

David Coulthard
BBC F1 co-commentator

"Hamilton is applying the pressure on Rosberg, who may well be trying to manage the tyres. If they are doing a two-stop strategy they will have to get into the lap 20 or mid-teens.

"Hamilton won't be able to spend a lot of time in the gearbox of Rosberg without eating into those tyres."

The McLarens of Jenson Button and Kevin Magnussen are having a shocker, having shown good pace earlier in the weekend. Button is down in 13th and under investigation for speeding behind the safety with Kevin Magnussen 0.8 seconds up the road in 12th. Sauber's Gutierrez and Lotus's Maldonado are also under investigation.

David Coulthard
BBC F1 co-commentator

"If Sebastian Vettel is attempting to do a one stop this afternoon he is going to have to be so gentle on these tyres. That is not conducive to overtakes. So this is going to be fairly gentle racing to start with."

Sebastian Vettel is currently 15th, 1.3 seconds behind Nico Hulkenberg.

Ashley Wilkinson, external: Not many have the fortitude to pull that move off on Fernando Alonso, of all people. Kudos, Danny!

Jay, external: It's amazing how drivers are still buying the same dummy Ricciardo's been selling for so many races now!

ML Shelton, external: Looks like Perez has scuppered his chances of renewing his drive next year.

Lewis Hamilton is told that he is safe on fuel - which means he doesn't currently need to drive conservatively to fuel save to get to the end of the race. The Briton immediately picks up the pace, pumping in the fastest lap of the race and closing to within just 0.6 seconds. Game on.

Nico Rosberg sets the fastest lap of the race to move 1.1 seconds clear of Lewis Hamilton in this 56-lap race. Here's the top 10 as it stands:

1) Ros 2) Ham 3) Mas 4) Bot 5) Ric 6) Alo 7) Rai 8) Mal 9) Ver 10) Gro

David Coulthard
BBC F1 co-commentator

On Ricciardo's move on Alonso: "That is why they practice the long runs with fuel on Friday. It's all about getting your confidence. It has won him back some of those places he lost off the start."

Nico Rosberg opens up a 0.7 second lead over Lewis Hamilton with Felipe Massa holding off an attack from Valtteri Bottas at Turn One to retain third. Fernando Alonso isn't so lucky, though, with Daniel Ricciardo steaming through to take fifth. Good recovery from the Australian who had a bad start and dropped back.

David Coulthard
BBC F1 co-commentator

"Hamilton got good reaction off the line at the start but you can see there is more traction on the right of the track. He might be surprised not to out-launch his team-mate Rosberg. But he will be relieved he wasn't out-launched by one of the Williams into Turn One."

Image source, Reuters

Good news, folks. The safety car will come in at the end of this lap. Nico Rosberg starts to back the field up, with Lewis Hamilton pulling alongside to remind his team-mate he's there. But the German then puts the hammer down and slightly catches Hamilton out.

The marshals are doing a good job of clearing the debris which means this race should be back under way shortly.

Jeremiah Kariuki, external: The only chance Sutil had to impress and probably score some points for the team are gone with that collision with Perez!

Sean Richardson, external: Shocking driving by Perez.

Jacques, external: Good start from the dirty side by Lewis, didn't lose any places, hope he repeats his performance from 2012.

Kevin Magnussen and Sebastian Vettel are among the cars to pit under the safety car. Nico Rosberg leads from Lewis Hamilton.

David Coulthard
BBC F1 co-commentator

"It was contact with Raikkonen that did it. He just misjudged the speed of the car in front of him. The safety car plays into the hands of Sebastian Vettel, who doesn't have to catch up to the back of the field. It increases his chances of getting points this afternoon."

So Nico Rosberg leads from Lewis Hamilton with Felipe Massa third and Valtteri Bottas fourth. Further back, there's contact - and lots of it, with Sergio Perez tapping the back of Kimi Raikkonen, which slings him into the unsuspecting Adrian Sutil. Sutil is out instantly, which is hugely disappointing considering his very strong qualifying performance.

Perez manages to get back to the pits, but his Force India is too badly damaged to continue. There's a lot of debris so the safety car is coming out.

Image source, AP

Nico Rosberg makes a clean getaway with Lewis Hamilton tucking into his Mercedes team-mate's slipstream before having a look up the inside. He's not close enough to make a pass, though, and it's as you were. Behind them, Felipe Massa gets past his Williams team-mate Valtteri Bottas for third.

The grid is set. One light, two lights, three lights, four lights, five lights - it's go, go, go!

Image source, Getty Images

Sebastian Vettel pulls out of the garage and crawls down to the end of the pit lane, where he'll start the race.

Andrew Benson
Chief F1 writer

"The US Grand Prix is looking like a two-stop race for the first time - it was an easy one-stop in both 2012 and 2013. Three stops are not much slower but it's believed most won't need to go that way. First stop timing is not critical but they are expected around laps 12-16 - and if someone is on a three-stop, it will only become apparent at their second stop, which would then be in the mid-20s rather than the early to mid-30s. Red Bull's strategy will be interesting.

"Might Daniel Ricciardo try to get ahead of the faster Williams cars by stopping early, trying to force them to respond and risk running into excessive tyre wear? And could Sebastian Vettel start on the harder 'medium' tyre from his pit lane position? Some strategists believe the world champion might even try a one-stop. There is a definite advantage for the drivers on the right-hand side of the grid, in the odd-numbered positions, but at four to five metres it is not quite enough to guarantee a place gain in the event of comparable starts for both drivers."