Novak Djokovic beats Carlos Alcaraz 4-6 6-4 6-3 6-4 to reach semi-finals
Aryna Sabalenka survives huge scare to beat Anastasia Pavlyuchenkova and reach semi-finals
Paula Badosa earlier stuns Coco Gauff in 'dream come true' moment
Alexander Zverev sees off Tommy Paul to reach last four
Jonathan Jurejko
BBC Sport in Melbourne
The guy making the public announcements on Rod Laver Arena sounds apologetic when he has to remind fans of the time.
It's fast approaching 1am.
Some will need to leave soon to get the last of the public transport home, he reminds them.
Not too many have budged.
*Djokovic 4-6 6-4 6-3 4-3 Alcaraz
Now then, Carlos Alcaraz steps into a backhand winner down the line before punching a forehand winner across court past a stranded Novak Djokovic.
It does feel like there's been a momentum shift.
Djokovic crashes a backhand winner of his own, before skewing a forehand wide after another punishing rally to offer two break points to Alcaraz.
*Djokovic 4-6 6-4 6-3 4-3 Alcaraz
Russell Fuller
Tennis correspondent on BBC Radio 5 Live and BBC Sounds
That was absolutely incredible. I loved the reaction from Carlos Alcaraz.
The scoreboard isn't giving him very much to smile about, but he was definitely smiling about that.
If he does get back into this match, he is going to remember that 33-shot rally, which would have given Novak Djokovic a double break advantage if he had won it.
I still think Djokovic is the most likely winner.
Image source, ReutersJonathan Jurejko
BBC Sport in Melbourne
The crowd are on their feet - they think it's all over...
Well, that 33-shot rally is. THIRTY-THREE!
Both players bend over double as they try to catch their breath.
Some of the fans need to catch theirs, too. Many rise and give a standing ovation to both men.
Alcaraz eventually just laughs. The crowd join in when they see his face pop up on the screen.
Image source, Reuters*Djokovic 4-6 6-4 6-3 4-3 Alcaraz
Carlos Alcaraz goes on to secure the hold after that remarkable rally and the noise levels increase further.
He points his finger to his ear in celebration.
Can the third seed carry his momentum into the next game and break Novak Djokovic's serve?
Djokovic 4-6 6-4 6-3 4-2 Alcaraz*
Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds
I do wonder how Novak Djokovic's leg is going to be tomorrow.
I wonder how he is going to wake up and whether he has taken painkillers here.
I wonder what's going on there...
Djokovic 4-6 6-4 6-3 4-2 Alcaraz*
A rally like that at this stage of the match is just ridiculous as both players put everything into all 33 shots.
It's Novak Djokovic who blinks, going long, and he takes his frustrations out on his coaching team.
Andy Murray looks on stone-faced, while Carlos Alcaraz can only laugh while the crowd is on their feet.
It's all happening.
Image source, ReutersDjokovic 4-6 6-4 6-3 4-2 Alcaraz*
Carlos Alcaraz misses a dropshot at a key moment and we move to deuce.
It's Novak Djokovic's pressure which is forcing the Spaniard into shots like that.
The Serb then brings up break point as Alcaraz goes into the net.
Djokovic 4-6 6-4 6-3 4-2 Alcaraz*
Carlos Alcaraz gets the luck of the bounce just at the right time as the ball trickles over the net, bringing a wry smile from Novak Djokovic and the game goes to its third deuce.
Another fine first serve from Djokovic prompts frustration from Alcaraz, before he holds as the Spaniard goes long with a return.
*Djokovic 4-6 6-4 6-3 3-2 Alcaraz
Carlos Alcaraz can't capitalise on a Novak Djokovic second serve, but whips a forehand down the line next point to force deuce again.
The crowd roar and Alcaraz laps it up, raising both fists and shouting "vamos!".
Image source, Getty Images*Djokovic 4-6 6-4 6-3 3-2 Alcaraz
We've just hit the three-hour mark - that has flown by.
Carlos Alcaraz goes long with two shots from the baseline before kicking out at the ball as it rebounds back to him.
The Spaniard fights back, prompting words of frustration from Novak Djokovic, and forces deuce with a dropshot which the Serb can't get over the net.
*Djokovic 4-6 6-4 6-3 3-2 Alcaraz
Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds
There is definitely a pep in the step of Carlos Alcaraz.
I think he has decided to change the tactics up here.
He is going into the corners and he is going to try to make Djokovic run as much as he can. He will be trying to get the ball out of his position.
Image source, Reuters*Djokovic 4-6 6-4 6-3 3-2 Alcaraz
Two lengthy rallies see Carlos Alcaraz come out on top, before he opens up a 40-0 lead with a forehand winner down the line.
He seals the game with an ace and now has the chance to put the pressure quickly back on Novak Djokovic's serve.
Djokovic 4-6 6-4 6-3 3-1 Alcaraz*
Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds
What a stroke of luck that was!
Carlos Alcaraz was just throwing himself into the court there, trying to get back into the point.
It was an incredible get from Novak Djokovic, at full stretch. He is almost like Mr Bendy at times when he is stretching for balls.
Image source, ReutersDjokovic 4-6 6-4 6-3 3-1 Alcaraz*
Novak Djokovic is being asked questions in this game by Carlos Alcaraz but he's answered them emphatically.
The Serb holds by somehow lobbing Alcaraz with a forehand from the back of the court, which forces a stumble from the Spaniard.
Oohs and ahs everywhere from the crowd at Rod Laver Arena.
*Djokovic 4-6 6-4 6-3 2-1 Alcaraz
Novak Djokovic's defence from the baseline comes through again as he saves break point by getting the better of a rally with Carlos Alcaraz going into the net.
The Serb raises both his arms in the air in celebration.
Deuce.
*Djokovic 4-6 6-4 6-3 2-1 Alcaraz
Carlos Alcaraz puts a backhand into the net before complaining to his coaching team.
The Spanish third seed fares better next point, whipping a forehand winner down the line before outplaying Novak Djokovic in a rally.
Alcaraz then earns break point as Djokovic double-faults.
Big moment.
*Djokovic 4-6 6-4 6-3 2-1 Alcaraz
Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds
It's just drifting away from Carlos Alcaraz, and somehow he has got to wrestle back control of the momentum.
That is going to be very difficult to do because Novak Djokovic has wrestled it in his direction and he is forging ahead. He is getting tougher and tougher to play against.
His level has been rising the whole of the match, whereas Alcaraz has slightly fallen off.
Jonathan Jurejko
BBC Sport in Melbourne
Traditionally the Laver crowd isn't collectively that rowdy.
Tonight is the same - but there are a few lone rangers who keep shouting out.
"Come on Rafa!" is the latest wisecrack. It brings a polite rebuke from umpire Eva Asderaki-Moore.
It's hardly as boisterous as a rock gig.
Talking of which, you could hear hairy Brit punk aggressors Idles crashing out their set earlier at the nearby Sidney Myer Music Bowl.
The second hottest ticket in town.
*Djokovic 4-6 6-4 6-3 2-1 Alcaraz
Carlos Alcaraz needs this game and serves like that will help as Novak Djokovic can't get near an ace down the middle.
The Spaniard celebrates with a fist pump before going on to hold as Djokovic puts a return long.
Image source, Reuter