Nadal shoots long as Medvedev goes 30-0 up on serve, before the Russian double faults.

Medvedev takes the next point but Nadal responds in lovely fashion, sprinting towards the net before sending him the wrong way.

Medvedev then nets a backhand and we're at deuce.

Andrew Jolly: Nadal standing so far back when returning here. Somewhere John McEnroe is screaming at Medvedev to hit an underarm first serve.

Nadal eases into a 40-0 lead before sealing the hold with a sweet, sweet ace.

Image source, Getty Images

Amy: Nadal so far.. 1) slicing 2) serve and volley 3) moonballing He’s is throwing the kitchen sink at Medvedev.

Once again Medvedev saves, making use of the width of the court with his winner. Nadal challenges but it was very much in.

This time it's Medvedev with the advantage and he takes it as Nadal overhits a forehand.

That hold will be a relief.

Medvedev brings up the advantage on his serve but doesn't capitalise, stretching for a Nadal return and going long.

Another double fault from the Russian and it's another break point for Nadal.

Image source, Getty Images

A bit of to me, to you at the net but it's Medvedev who pokes home to save the first break point.

He then saves the second with a serve-and-volley. Nice.

Deuce.

A couple more errors are starting to creep into Medvedev's game. He fluffs the opening point of his next service game but then Nadal goes and does the same with another mis-hit.

Two more bad Medvedev errors follow and it's two break points for Nadal.

Jeff Tarango
Former professional tennis player on BBC Radio 5 Live

What I really love about this match so far is that both players are playing their service game as if they're the pilot of Air Force One.

A call of "VAMOS RAFA" from high up in the Arthur Ashe crowd creates a ripple of noise around the court.

An easy love hold for Nadal.

Nadal's first serve in percentage is currently only 37%.

Medvedev's is 71%.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Paul Bettany in the house. Picking up a few tips for his next Wimbledon appearance, no doubt...

The Brit produced a marvellous display on Centre a few years ago...

Image source, Getty Images

Seun: It's fair to say that there are not a few Federer fans cheering for Medvedev tonight. The Russian hasn’t had this level of support throughout the two weeks at Flushing Meadows.

Daniel Knight: Rafa already getting a lot of joy with those looping forehands to the back of the court. Medvedev is going for winners as soon as ones comes to him which is the wrong decision

A Medvedev serve looks to go out after a fault. It's called in but Nadal challenges, and Hawk Eye proves he was right to do so. That's Medvedev's first double fault of the night.

He levels and on the next point, a Nadal backhand bounces back off the net post.

Nadal then has Medvedev scrambling around the court, the Spaniard is at the net when Medvedev's goes for the cross court shot. All Nadal has to do is poke it down the middle but he fires long! He doesn't look happy with that. Is he nervous?

Medvedev holds.

Russell Fuller
BBC tennis correspondent at Flushing Meadows

A fascinating start.

Jeff Tarango
Former professional tennis player on BBC Radio 5 Live

I am completely convinced that Nadal misses his first serve on purpose, 20 per cent of the time, to get a bit of rest.

He's so upset about this shot clock thing that he needs extra time.

Image source, Getty

Nadal eases into a 40-0 lead courtesy of a couple of Medvedev errors and then holds to love as the Russian nets.

Rafael Nadal has found his rhythm.

Sulaimon Adelekan: Medvedev is giving as good as he gets. Not shying away.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Found a fellow Brit...

Catherine Zeta Jones is sitting in a posh box behind the media seats, alongside husband Michael Douglas.

He’s popped up from Wall Street for the occasion...

Image source, BBC Sport

Russell Fuller
BBC tennis correspondent at Flushing Meadows

Medvedev did so well to defend and defend and defend again, but eventually the dam burst.