You can hear the groan from Djokovic every time he is pushed from side to side, those trademark spins and slides just not there.

Still, he gets himself to 30-30 as Fritz puts a backhand into the net.

Djokovic batters down ace number 14 and then follows it up with double fault number five. Ouch.

Still, that's the only blip for the world number one, putting himself on top with a dinky drop shot before sealing a hold with another ace.

Djokovic can't run from side to side, and Fritz takes advantage to hold to 15.

And yet, after that poor game, Djokovic looks strong on serve.

He bangs down first serve after first serve, which Fritz can do nothing with, and an ace wraps up a love hold.

Laura Robson
Former British number one on BBC Radio 5 Live Sports Extra

You have a knowledge of how your body feels when you are healthy and you know when something is not right.

Djokovic knows his body better than anyone but it still out there and that tells me that possibly it's not that bad.

Djokovic, still feeling his side, larrups some service returns long, before putting a flat-footed forehand into the net.

A love hold for the American.

Ouch!published at 13:01 Greenwich Mean Time 12 February 2021

13:01 GMT 12 February 2021

Djokovic 7-6 (7-1) 6-4 3-6 4-6 1-0 Fritz*

Ooft.

Fritz goes down the line, Djokovic chases after it and lets out a yell as he stretches just a tiny bit to meet the ball. He composes himself at the side of court.

More like it from Djokovic, a whirling drop shot that Fritz can't get underneath.

Down the T goes Djokovic, and some aggressive hitting from the Serb hands him a hold.

Miles Maclagan
Former British Davis Cup player on BBC Radio 5 Live Sports Extra

Taylor Fritz will now be thinking who am I up against now? Where did those forehands come from.

Both players get themselves on the board with a pair of forehand winners, before Fritz larrups a backhand long.

A little bobble off the net goes Fritz's way and Djokovic drops to one knee as he tries to stretch to meet the ball. Ouch.

Nice! Good move forward from Fritz, and he volleys over a winner. Djokovic throws down his racquet and looks utterly filthy with himself. Hmm. 40-40.

Djokovic is grouching at his support box, but I'm not sure what he's expecting them to do.

He did seem to be able to swing his arms and serve better after the break for fans to leave.

He'll serve to start this decider.

And to a fifth set we go!

It feels creepy now there are no fans in, especially after the Kyrgios v Thiem match. The only thing you can hear is the squeak of the players' shoes.

Fritz has two set points to play with.

Wallop. Ace.

And again!

30-0.

Everyone is falling apart - the trainer has jus been out for Fritz for a bit of treatment on his left foot.

Djokovic is doing some stretching behind the baseline. Here we go.

Novak Djokovic starts his own service game with a double fault, before he gets on the scoreboard with a nicely popped away winner.

He holds to 15, and Fritz will have to serve this set out.

Djokovic has stopped wincing after every forehand, which is a positive sign for him.

Taylor Fritz picks a terrible time to double fault, but he still holds to 15, and Djokovic will serve to stay in this set.

Maybe Djokovic is fine after all. Back-to-back aces and a speedy hold for the two-time defending champ.

I guess the plus side of there being no fans is that the rowdy group who were jeering Djokovic have gone on their merry way,

He doesn't look right at all, his serve not fluent, but he clonks down an ace for a 30-0 lead.

Djokovic looks to have drop shotted his way to a winning point but Fritz, despite looking like the most ungainly tennis player on the planet, manages to chase his way back into the point for 30-15.

A nice down the line winner from Taylor Fritz ends a rally, with Novak Djokovic maybe moving a little better?

The arm swing isn't there though. Fritz holds.