David Law
Commentator on BBC Radio 5 Live and BBC Sounds

De Minaur hasn't won a set in the last seven meetings between these two, that in itself is glaring isn't it and frankly the sets haven't even been close either.

Image source, Getty Images

If Jannik Sinner needed a pick-me-up after struggling his way through his fourth-round match, a quick look at his record against Alex de Minaur might well have done the trick.

The Italian has won all nine meetings - and claimed another victory by walkover - between the pair, only dropping one set of the 21 they've played.

Jonathan Jurejko
BBC Sport in Melbourne

Shaking in his chair and more pale than usual, Jannik Sinner looked a real mess during his win over Holger Rune on Monday.

Morning after the Christmas party vibes. Sinner certainly wouldn't have been on the lash.

Rumours have been swirling around Melbourne all day about his physical condition, but he looks fresh enough as he wanders in the underbelly of Rod Laver Arena and kicks a ball with his fitness trainer in a warm up.

Proof will be in the pudding. De Minaur, a Duracell Bunny of a player, is bound to be testing out his condition.

Big cheers for Alex de Minaur as the Australian walks out at Rod Laver Arena for his first quarter-final at his home Slam.

The reception for Jannik Sinner is pretty generous, too.

De Minaur wins the toss and opts to receive first.

Image source, Getty Images

Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds

One of Alex de Minaur's greatest assets is his athletic ability and his speed around the court. He is going to need those wheels against one of the best, if not the purest ball striker that's out there on the tour right now.

It's venomous the way Jannik Sinner hits the ball, so clean, it has so much aggression, it's impossible to get him out of position and he just outmanoeuvres and out strikes so many opponents.

Jonathan Jurejko
BBC Sport in Melbourne

Image source, BBC Sport

Anticipation has the habit to set you up for disappointment in evening entertainment.

But tonight there will be some love... for Alex de Minaur, at least.

We can expect a partisan home crowd as De Minaur looks to become the first Aussie to reach the men's semi-finals in Melbourne since 2005.

You can spot Aussie flags, shirts and bush hats everywhere outside a buzzing Rod Laver Arena.

Thanks Pierce. What's the set-up like? Is your boss going to notice you following the tennis on the sly?

Right now we're seeing TV shots of the players going through their final warm-ups in their dressing rooms.

It's almost time.

Image source, Getty Images

Iga Swiatek said she "wasn't sure" if it was a double bounce after it was suggested she should have conceded the point.

"It was hard to say because I was full sprinting. I don't remember even seeing the contact point," said the Polish second seed.

"I don't know. Sometimes you don't really look when you hit the ball.

"I thought this is like the umpire's kind of job to call it. I was also waiting for the VAR, but I didn't see it so I just proceeded."

"I think we should be able to see it afterwards," reckons Emma Navarro.

"It happened so fast. In the back of your head you're like, 'OK maybe I can still win the point even though it wasn't called'.

"It's going to be a downer if I stop the point and it turns out it wasn't a double bounce.

"It's tough."

Image source, Getty Images

So, what do we think about double-bouncegate?

Not the name, I know that's solid.

But where do you stand on video replays, and should you need to challenge mid-point, or at the end of a rally to use them? Get in touch using the usual methods above.

Jonathan Jurejko
BBC Sport in Melbourne

Image source, Getty Images

A clear double bounce in the Australian Open quarter-final between Iga Swiatek and Emma Navarro has reignited the debate over how tennis uses video technology.

Navarro lost a point when she trailed 6-1 2-2 A-40 despite the ball bouncing twice in front of a stretching Swiatek, who went on to win 6-1 6-2.

Because Navarro continued playing, instead of immediately stopping the point, the American eighth seed was unable to challenge the call.

The Australian Open has introduced a video review system for the first time this year - but it can only be used on a point ending call or when a player stops play.

Afterwards Navarro said the incident did not "cause a momentum swing" but still believes there should be a change to the system.

Jonathan Jurejko
BBC Sport in Melbourne

Gonna be about half an hour until Sinner takes on the Demon.

Rod Laver Arena is getting a clear out and a clean up after the day session.

The players will be walking out at 20:15 local time (09:15 GMT)

We'll build up to Jannik Sinner's match with Alex de Minaur in a bit, that one will be next on Rod Laver Arena but they'll need some time to get the court ready.

In the meantime, I want to get your thoughts on what I've started to call double-bouncegate.

Shelton takes off his white wristbands and chucks them into the crowd.

He's in a two-tone highlighter pink and yellow top. You can't miss him.

He tells the crowd this was one of his favourite ever matches.

Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds

That was pure entertainment, what a wonderful handshake that was at the end as well - a wonderful embracement, words at the net, mutual respect.

It was scintillating tennis, neither of us knew who was going to come out on top, it was absolutely brilliant.

Ace Shelton. Two match points.

Sonego responds by taking the next point, but then Shelton slaps an absolutely peach of a winner which kisses the line.

Oh, drama! Ben Shelton somehow gets to a crosscourt wide one, almost landing in the stands.

On the floor on his belly, he has to concede the point, but has a laugh with the crowd by doing a few press ups before he gets back to his mark.

This is what we love about tie-breaks, how quickly things can change.

A couple of gifts from Lorenzo Sonego who overhits two points long. Ben Shelton is ever so slightly back in charge.