Alexander Zverev can't seize his first opportunity but Novak Djokovic, who evidently has still not quite found his range yet, misses the baseline to grant the German another chance.

No! Huge frustration for Zverev as he nets a groundstroke.

With Djokovic continuing to struggle with his first serves, break point number three is up...

Alexander Zverev is dialled in from the start here and puts away a backhand for 0-30 on Novak Djokovic's serve.

A bit of early pressure for the former world number one to deal with, but he restores parity with an ace.

That's loose though! Djokovic misses a backhand to hand Zverev the first break point of the contest.

Image source, Getty Images

Jonathan Jurejko
BBC Sport in Melbourne

It will be a difficult afternoon for Novak Djokovic if he continues to miss first serves.

Djokovic did not land one in his opening service game, nor the first two points of the next one.

Luckily his second serve - which was aggressive and precise against Alcaraz - is continuing to dig him out of bother.

Andy Murray gave an approving smile after Novak Djokovic won that entertaining final point to get himself up and running in this first semi-final, receiving plenty of applause from the crowd for his efforts.

Alexander Zverev crashes down his first ace of the afternoon to take charge in his first service game and buries a forehand winner into the corner in a promising start as he too gets on the board.

Good signs. Both players look very up for this.

Jonathan Jurejko
BBC Sport in Melbourne

Image source, Getty Images

Whether it is providing detailed insight about an Australian Open opponent or carrying his racquets to the stringer, Andy Murray has got Novak Djokovic's back.

The recently retired Briton has even been chasing down drop-shots at the end of practice sessions.

Over the past fortnight in Melbourne Murray has shown he is willing to do whatever it takes to help Djokovic win a record 25th Grand Slam title.

"They're in this together," Murray's former coach Dani Vallverdu told BBC Sport.

"It's the feeling of the older guys against the younger guys - that's what's driving them."

BBC Sport looks at what we have gleaned so far about one of the most intriguing player-coach partnerships in tennis history.

Just a 27-shot rally on the second point of the match, with Alexander Zverev drifting a backhand wide after taking the opening point on Novak Djokovic's serve.

Djokovic overhits from the baseline to give Zverev hope at 40-30 but the Serb shows his movement won't be affected by the strapping on his thigh as he zips around the court to outlast his opponent and get the opening hold of serve.

Image source, Getty Images

Novak Djokovic is wearing heavy strapping around that left thigh.

Will it cause him any issues, or is it just precautionary?

The sun is beaming down on Rod Laver Arena as the players take to the court for the first men's semi-final.

Away we go.

Jonathan Jurejko
BBC Sport in Melbourne

We're all intrigued to see what shape Djokovic will be in today.

The 10-time men's champion had not practised at Melbourne Park since Tuesday night's remarkable quarter-final win over Carlos Alcaraz -

Djokovic was supposed to practice yesterday afternoon, but disappeared off the schedule about lunchtime and did not hit as planned.

Don't read too much into it, though. Djokovic also didn't practise between matches in his run to the 2023 title - then revealed he had a 3cm tear in his hamstring.

Image source, Getty Images

Alexander Zverev continues his bid for an elusive first Grand Slam title.

The German second seed previously reached the semi-finals at Melbourne Park in 2020 and 2024.

He is into his ninth Grand Slam semi-final - the most among active players who have not won a major.

His victory over Tommy Paul was the 27-year-old's seventh in a row and continued his unbeaten start to his season.

Zverev, clearly, is in great form. But will it prove enough to topple the might Novak Djokovic at the Serb's favourite Slam?

Jonathan Jurejko
BBC Sport in Melbourne

We know Novak Djokovic prefers later starts at the Australian Open, but today he has no choice.

With Djokovic and Zverev having played their quarter-finals on Tuesday, they have to play in the first of the semi-finals.

Don't think the afternoon sun should pose too much of a problem, though.

At the moment there is some cloud cover and temperatures are only about 21C - cool by Melbourne summer standards.

Image source, BBC Sport

Image source, Getty Images

A few days before the Australian Open started, Novak Djokovic and Alexander Zverev played out a light-hearted 'Night with Novak' charity match.

This latest meeting on Rod Laver Arena will have a very different feel.

In competitive meetings, Djokovic holds the edge with eight wins in 12 meetings with Zverev, while he also won the pair's only Australian Open meeting, in the quarter-finals in 2021.

Victory for Djokovic would be his 100th at the Australian Open, joining Roger Federer as the only two men to achieve 100 singles wins at the tournament.

It would also take him through to a record-extending 11th Australian Open final and 38th Grand Slam final.

Jonathan Jurejko
BBC Sport in Melbourne

Image source, BBC Sport

Here's Novak Djokovic!

After going into stealth mode over the past couple of days, the seventh seed returned to the Melbourne Park courts about an hour ago.

Under the watchful eye of coach Andy Murray, he hit with Australian teenager Hayden Jones for about an hour - with several hundred fans packing into court 16 to watch.

Djokovic was wearing strapping on his upper left leg and moved OK without fully exerting himself.

To the delight of the fans, the session ended with Murray getting on court to fire down some meatier serves.

Image source, BBC Sport

Well done if you've managed to get yourself up in time for the start of today's action if you're in the UK!

Here's what we have to look forward to.

First on Rod Laver Arena, record 10-time champion Novak Djokovic looks to maintain his bid for an outright record 25th major title against German world number two Alexander Zverev.

They are followed by defending champion Jannik Sinner's meeting with American 22-year-old Ben Shelton.

Morning!

A huge day of action is about to get under way in Melbourne, where the four remaining players in this year's men's singles draw will bid for a place in Sunday's final.

But there is still a lot of work to do to reach that goal.

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images