That's much better from Alex Michelsen who comes into the net to land a deft backhand volley.

The American then outplays Alex de Minaur, overpowering him from the baseline to earn break point.

De Minaur does brilliantly to save it as he drives a backhand winner past Michelsen when it looked like he was in trouble.

Image source, Getty Images

American eighth seed Emma Navarro has come through a back-and-forth tie with Russian ninth seed Daria Kasatkina to reach the quarter-finals.

The 23-year-old has won 6-4 5-7 7-5 in a match which saw countless breaks of serve.

Navarro will face Polish second seed Iga Swiatek in the last-eight after her 6-0 6-1 win over lucky loser Eva Lys earlier today.

Alex Michelsen hasn't been at his best so far today but take nothing away from Alex de Minaur, who is returning almost everything.

He gets the better of a 22-shot rally to earn two more break points, but Michelsen saves both.

Michelsen then comes through to hold as De Minaur puts a forehand long.

Alex de Minaur is aiming a lot of his serves at Alex Michelsen's body and the American hasn't been able to combat it so far.

A brisk hold to love for the Aussie.

Ryan Harrison
Former American tennis player on BBC Radio 5 Live and BBC Sounds

If I'm in the coach's corner for Alex Michelsen, it is about building momentum now.

Even if you aren't able to turn this set around and get the break back, you just want to start making some headways, particularly on your own service game.

He has been serving and trying to hit aces, but Alex de Minaur has been all the way stretched out and getting those returns back. I would like to see Michelsen going a little bit more to the body and in the middle of the court, with a slightly different style.

Frustration is building for Alex Michelsen as he drops his racquet to the ground - I wouldn't class it as a racquet smash but it was close.

The American is taken to deuce again by Alex de Minaur before he serves his first ace of the match.

Michelsen then comes through a rally to hold as De Minaur finds the net - he's on the board!

Ryan Harrison
Former American tennis player on BBC Radio 5 Live and BBC Sounds

Alex de Minaur is starting this second set off with another break and a hold, much like the first set started.

It's going to start to feel like a real uphill battle for the young American Michelsen. It has certainly not been the debut on Rod Laver that he was looking for.

Alex de Minaur is just a relentless guy. His entire energy and persona is just relentless, he just doesn't give you an inch and he is ready to pounce at you at all times.

Alex de Minaur consolidates his early break in the second set with a fairly trouble-free hold.

The first point of the second set sees a 20-shot rally which Alex de Minaur gets the better of.

The Aussie then wins the point of the match so far, somehow keeping the point alive to come into the net and guide a backhand winner past Alex Michelsen.

Michelsen is playing better now but De Minaur's defence is so good and he goes on to secure the early break.

The TV cameras zoom in on an insect, which looks something like a bee or wasp, walking around the court - watch out guys.

Meanwhile, Alex de Minaur is taken to deuce but comes through to wrap the first set up inside 27 minutes.

American Alex Michelsen hasn't been in this match so far.

Image source, Reuters

Alex de Minaur breaks again with Alex Michelsen finding the net with a forehand.

The Australian eighth seed will serve for the first set with Michelsen yet to get on the board.

Two-time Grand Slam winner and fellow Australian Lleyton Hewitt is watching Alex de Minaur from courtside.

He will like what he sees so far as the eighth seed wins his fourth consecutive game.

Alex Michelsen is being outplayed during the rallies.

At 6ft 4in, American Alex Michelsen's serve is a weapon and he lands a couple of good ones to ease into a 40-0 lead.

Alex de Minaur fights back to deuce though as Michelsen struggles with unforced errors - that's eight inside the first three games.

De Minaur secures his second break as Michelsen puts a backhand into the net.

Alex De Minaur has started well here, while Alex Michelsen hasn't quite found the range on his shots just yet.

Australian eighth seed De Minaur holds to love as Michelsen loops a forehand long.

Two early break points for Alex de Minaur and he makes them count at the second opportunity.

His celebratory fist-pump is greeted by a polite round of applause from the crowd on Rod Laver Arena.

Image source, Getty Images

The final match on Rod Laver Arena today is under way and it sees unseeded American Alex Michelsen take on Australian eighth seed Alex de Minaur.

De Minaur is the last remaining Aussie left in the singles draws so you can expect strong support for the 25-year-old.

Michelsen, 20, had never previously been past the second round at a Grand Slam before his run this year.

A quarter-final tie with Italian top seed and defending champion Jannik Sinner awaits the winner.

Image source, Getty Images

American 19th seed Madison Keys knocked out 2023 runner-up Elena Rybakina with a 6-3 1-6 6-3 win to reach the quarter-finals.

Keys will face Ukraine's Elina Svitolina, who stormed to a 6-4 6-1 win against Russian Veronika Kudermetova.

In the men's draw, defending champion Jannik Sinner struggled physically before moving past Denmark's Holger Rune.

Italy's Lorenzo Sonego beat American qualifier Learner Tien 6-3 6-2 3-6 6-1 to reach his first Grand Slam quarter-final.

Sonego will play 21st seed Ben Shelton next after the American's fourth-round opponent, Frenchman Gael Monfils, retired while trailing 7-6 (7-3) 6-7 (3-7) 7-6 (7-2) 1-0.

Before we turn our focus to Alex de Minaur v Alex Michelsen, let's have a quick recap of what's happened so far today...

Iga Swiatek speaking on court after reaching the semi-finals: "That was my first night session so I'm happy I got the chance to play on Rod Laver with such an amazing atmosphere. I enjoyed it so that's the most important thing.

"Thank you guys for coming - not only the Polish fans because it is almost a full stadium today."

On how much more she feels she can improve: "I'm still 23 years old, so there is a lot to improve always. I don't feel like I'm in my peak yet but matches like that definitely give me confidence. I feel like I'm playing a good game.

"Usually I don't feel comfortable with my game at the Australian Open, but this year it is a bit better. I'm just enjoying being on the court and off the court as well because I definitely have a good time here. Hopefully it's going to last even longer.

"We don't know what is going to happen in the future, maybe I will be better, but I'm glad that I'm able to play my game and for sure win. It makes an impact on how I feel on the court."

We'll bring you Iga Swiatek's quotes shortly, but don't go anywhere!

Alex de Minaur is the last Australian standing and he's going to be on Rod Laver Arena next to take on American Alex Michelsen.