In case you missed any of that:

• Carlos Alcaraz looked on course for victory when he led by two sets
• Serving at 4-4 in the third, he suddenly pulled up and was barely able to move
• The world number one managed to go within two points of a three-set victory on Alexander Zverev's serve
• Zverev battled back to force a fifth set with Alcaraz still struggling with cramp
• Zverev went an early break up in the fifth set and served for the match at 5-4
• Alcaraz broke to get the match back on serve and then capitalised on Zverev's nerves as the German served at 6-5 down to try to force a 10-point tie-break
• At five hours and 27 minutes, it was the longest semi-final in Australian Open history

Jonathan Jurejko
BBC Sport tennis news reporter in Melbourne

Goodness knows what is going through Zverev's mind right now.

He must be frazzled. He looked dazed and confused as he trudges back to the locker room.

There have been some heartbreaking defeats in the German's career - notably three Grand Slam final losses.

This surely ranks just below them.

All of us after watching that match.

Image source, Getty Images

On what it would mean to win on Sunday, Carlos Alcaraz says: "I am really happy to have the chance to play in my first final in Melbourne.

"I couldn't be here right now without these guys [the crowd] it's a pleasure playing in front of all of you. The way you pushed me back into the match on every ball, every point is crazy.

"Hopefully it will be a good support on Sunday and a great atmosphere, I can't wait.

"Right now, my head is on recovering and trying to be in a good state to put on a show on for you.

"See you on Sunday."

Image source, Getty Images

Speaking after his five-set victory over Alexander Zverev, Carlos Alcaraz said: "I always say that you have to believe in yourself no matter what you have been through.

"I was struggling in the middle of the third set and physically it was one of the most demanding matches I have played in my career.

"I have been in this kind of match before and I knew what I had to do, I knew I had to put my heart into it.

"I did it and fought until the last ball.

"I am extremely proud in the way I fought back in the fifth set."

Image source, EPA

Carlos Alcaraz writes 'Believe :)' on the TV camera lens.

The Spaniard's brother joins him on the court to help him with his bags before he hobbles off the court.

Now it's about how he's going to manage to recover in time for Sunday's showpiece.

We'll bring you his thoughts on that remarkable semi-final next.

Russell Fuller
BBC tennis correspondent on BBC Radio 5 Sports Extra

An Australian open devoid of drama has just produced one of the most dramatic tennis matches you could ever wish to see.

Cramp was a very significant factor in that - Zverev came storming back but after five hours and 27 minutes he is in his fourth consecutive Grand Slam final, and an Australian Open finalist for the first time.

Jonathan Jurejko
BBC Sport tennis news reporter in Melbourne

Cabeza, corazón y cojones.

Carlos Alcaraz shows everything which his grandfather preached to him.

Head, heart and... courage, shall we say.

Alcaraz prods his chest to indicate this victory came from the heart.

We've seen some extraordinary things from this 22-year-old kid from Murcia already in his career - and here's another one.

"Believing, believing all the time."

Carlos Alcaraz's response when he's asked how on earth he came through that to reach his first Australian Open final.

This is, of course, the player who came back from two sets and three championship points down to win last year's French Open epic.

But I'm not sure we've ever seen him suffer physically like he did out there today, having played in 30C for the first two or three hours of it.

Image source, Getty Images

Matches like that don't come around very often.

In truth, we've been starved of truly thrilling, edge-of-your-seat matches at this year's Australian Open.

But that wasn't half worth the wait.

Carlos Alcaraz looked down and out. The man could barely move.

That was about three hours ago.

After five hours and 27 minutes on court, he has somehow found a way to win that fifth set.

Remarkable.

Carlos Alcaraz has match point.

I repeat. Match point Carlos Alcaraz.

Carlos Alcaraz gets to 30-30 and back within two points of victory, just as he was in the third set. That seems a lifetime ago.

The TV cameras show Jannik Sinner wandering the hallway inside Rod Laver Arena as he awaits to find out when he and Novak Djokovic might get on.

Alcaraz follows Zverev to deuce.

Jonathan Jurejko
BBC Sport tennis news reporter in Melbourne

If Zverev loses this, I reckon we might see the racquet smash of all racquet smashes.

Now the pressure really is on Alexander Zverev.

Having tried, and failed, to serve out the match, he must now serve to stay in it.

Epic doesn't come close to describing it.

Where this goes next, I really wouldn't like to hazard a guess.

Whatever has gone before, these two must now scrap it out with the diminishing reserves they have left to get over the line.

From two sets up, to a break down in the fifth, Carlos Alcaraz hits the front in the decider to secure himself a tie-break at the very least.

Jonathan Jurejko
BBC Sport tennis news reporter in Melbourne

Zverev bends over double and searchingly looks to his team for answers.

Facing back-to-back break points for the first time in the decider left him too much to do.

It feels like the momentum is firmly with Alcaraz now...

Image source, Getty Images

Oh my goodness me.

He has done it! Somehow.

We're not done yet, folks. Carlos Alcaraz, back from the brink, is still alive in this record-breaking semi-final encounter.

The Spaniard lifts his arms in the air as the crowd rise to their feet.

TWO BREAK POINTS FOR CARLOS ALCARAZ.

Just as this officially becomes the longest ever Australian Open semi-final.