Oh no. Alexander Zverev is down.

He's clutching his left knee.

Jannik Sinner had wrong-footed him with the drop shot.

Alexander Zverev holds his hands on his hips and glares up at his team. He knew how big of a chance that was, but Jannik Sinner aces to move 40-30 up.

An inside-out forehand winner down the line from the German gets us to deuce though.

And now he's got break point as Sinner nets!

Alexander Zverev holds his head in his hands after planting into the net. 30-30.

Now the door opens for Alexander Zverev after Jannik Sinner double faults and then sends a forehand wide. 0-30.

Marion Bartoli
Former Wimbledon champion on BBC Radio 5 Live

Image source, Getty Images

You just feel the energy level of Zverev is starting to come back slightly.

He is on his toes right now, bouncing around.

Groans from the crowd as Alexander Zverev, after taking an age to step up to the baseline, is interrupted by a shout from the crowd. His ball toss goes wayward, he has to do the whole routine over again and ultimately fires long.

An ace gets him back on track, though, and he holds. That was good bit easier than his last couple of service games.

Andre Agassi
Former Wimbledon champion on BBC One

It feels like it is starting to lean a little more towards Sinner now. I think he has stopped allowing Zverev to dictate. When he gets into the point, he starts controlling it. That’s an accumulative effort. But they are still small margins.

Image source, PA Media

Another game point goes missing for Jannik Sinner because of an unforced error. A bit too eager to seal a love hold.

But he gets the job done on the next point.

Pat Cash
Former Wimbledon champion on BBC Radio 5 Live

A little harder for Zverev to hold serve at the moment. Sinner, again, just improving his dominance at the back of the court. So crucial for Zverev to hang in there.

After flinging a forehand wide, Alexander Zverev gets the better of Jannik Sinner with two huge first serves.

But the Italian isn't going away in the German's service games and clatters a down-the-line winner to move level at 30-30.

Zverev sees himself through, though, with another big serve that Jannik Sinner skews wide.

Jamie Murray
Seven-time Grand Slam doubles champion on BBC One

It is going to be a very physical match from here on in. It has been at such a high level. Zverev came out with a plan and he has been sticking with it.

One excellent return from Alexander Zverev, but that's all Jannik Sinner allows as he holds to 15.

The defending champion looks a whole lot more confident now.

Russell Fuller
BBC tennis correspondent on BBC Radio 5 Live

Zverev is still landing 80% of his first serves and that is probably keeping him in the final right now.

Image source, Getty Images

Alexander Zverev was under pressure there, but his serve comes up clutch and he finds a way through.

His head has dropped a bit after the second-set tie-break, so he really needed to avoid dropping serve early doors in the third.

The ball clips the net tape and Jannik Sinner can't adjust his feet quickly enough and the forehand fizzes wide. 30-30.

Jannik Sinner lets a return zip down the line to open up a 0-30 lead, but the drop shot comes up short again. 15-30.

Pat Cash
Former Wimbledon champion on BBC Radio 5 Live

It just feels like Sinner has got a bit more control at the back of the court, which had been very even up until the end of the set. Looking just a bit more comfortable in those rallies, Sinner, but he's still got to hit great shots.

The big challenge now is breaking Zverev's serve.

Andre Agassi
Former Wimbledon champion on BBC One

You get the feeling the edge is coming off Zverev and Sinner feels he can turn this match right now

Jannik Sinner looks to be on his way to a straightforward love hold before sinking a drop shot into the net.

But he redeems himself on the next point, lifting a much better drop shot over and well out of the reach of Alexander Zverev.

So, we've got at least two more sets of tennis ahead. Settle in, it could be a late one!

Jannik Sinner is back out on court and ready to go...