Is this the pat-a-cake shot we discussed earlier? Thiem tries to pat over a volley and Medvedev almost gets there. Smash it, man! Lucky.

Tie-break time!

Medvedev winds up some bludgeoning forehands which Thiem continues to bat back, until one veers off into the tramlines.

Canny stuff from the Russian, who dinks down a 108mph serve out wide.

"Come on!!" he shouts to himself.

Thiem licks the paint with a return for deuce part deux...

You feel that last game could be big.

Oooh! Ouch! Thiem takes a tumble on the baseline as he scampers after a Medvedev returns. Hopefully he is fine. He is.

Back on his feet... Thiem claws the game back to 40-30 when the Russian cracks a forehand into the net.

Then he does the same from the deuce side of the court... 40-40.

This is the first time that Thiem is ahead in the second set.

Medvedev, who failed to serve it out at 5-4, is serving to stay in it...

And then a fifth break point for Medvedev. This is the longest game of the match, I'd suggest.

Thiem's thumping forehands rock Medvedev again, pure aggression from the Austrian.

That earns a sixth deuce and finally Thiem swats away the Russian.

The break points are arriving for Medvedev quicker than Subway trains at Grand Central. He can't take the fourth either!

Neither can Thiem get over the line, a deep forehand rocking the Austrian who bats back into the net.

Deuce for a fifth time...

Thiem saves one. But here's another... saved too. Medvedev can't believe he's hit the net.

Moments later he gets a third chance... this is tense... big moment here...

Backhand to backhand from the baseline, Medvedev becomes impatient and mixes it up with a vicious slice... into the net. Deuce.

Blimey O'Reilly! Some ferocious hitting from both men. The balls will be bruised at this rate.

Thiem roars a roar of frustration as he can't put away a volley... 15-30.

Two points later there is no anger, just disappointment in himself. A double fault brings up a break point for Medvedev...

Danger! Danger! High voltage from Thiem as he crunches a forehand return which Medvedev can't knock back to safety.

Then Medvedev decides to serve and volley, planting into the net...

Two break points for Thiem... he nabs the second. Medvedev whacks a forehand into the net.

In the nick of time for the Austrian! As you were.

So here we are, as Bloc Party once said.

Daniil Medvedev is serving for the set.

Oh my word. Medvedev knocks a winner down the line which is almost travelling at the speed of light. Almost.

That's 0-30 after Thiem opens with a double fault.

But wait! The Austrian isn't rolling over. Strong fightback clinches the hold and asks the question of Medvedev...

Right then Domi, you're serving to stay in the set.

I think he knows that.

Thiem is virtually off the dancefloor as he awaits a Medvedev serve. He's stood almost next to the line judge. Two metres away, of course.

A splendid, spindly backhand return from deep comes back at a sharp angle and Thiem can only bat into the net.

Brilliant from the Russian.

"Walk this way, talk this waaaaaay!"

Run DMC and Aerosmith blasts out at the changeover.

Both players have been "singin' hey diddle diddle" at various points in this match.

Currently it is Medvedev grooving, crashing down a 127mph ace for 40-0...

Aaaaah! I could watch that Thiem backhand on repeat all day. Looks even better in slo-mo.

Medvedev still wouldn't have caught that one, either. Inch perfect precision.

That helps the second seed to hold to love, but he still faces work to stay in this set.

Just as things were getting dicey again for the Russian, he digs out a couple of big first serves - one 125mph down the middle and another slightly hotter one out wide - to seal the hold.

Half a chance here for Thiem. Medvedev leads 30-0 before the Austrian fights back to 30-30 thanks to two unforced errors... keep it calm, Daniil.

From 30s to deuce...

What do we reckon Zverev was doing on his phone?

Messaging his mother? Checking what the Twitterati was saying about him? Reading the BBC Sport match report?

Probably on a dating app.

Alexander Zverev is certainly chilled. Feet up, shoes off, checking his phone, sushi about to arrive on his Ashe balcony.

Eyes up, Sascha. Your good pal Domi has just held to love.

Those two have been dreaming about playing against each other in a Grand Slam final. Is it going to happen?