Alex de Minaur follows up winning the second set by holding his first game in the third on serve.

Both players are striking the ball well now but it's the Australian who is edging the rallies.

Alex de Minaur wastes no time, returning to convert the set point!

The Aussie gees up the home crowd on Rod Laver Arena, shouting "let's go" as the noise levels increase.

He is one set away from a first Australian Open quarter-final.

Image source, Getty Images

Some strong serving sees Alex Michelsen win two points and put the pressure on Alex de Minaur but he responds brilliantly, somehow finding a home for a forehand winner across court.

The Australian then serves an ace to bring up set point.

We're all square at the change of ends as Alex de Minaur once again aims his serve into Alex Michelsen's body and the American can't get his return in play.

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

I think Alex de Minaur has got this tie-break, just simply off the fact that he has got the crowd behind him again.

I always look at tie-breaks in terms of who is going to give away fewer free points. I can see Alex de Minaur making a lot of returns and making Alex Michelsen suffer through some of his service points.

I think De Minaur has got this one 7-3.

The pair exchange points on serve before Alex Michelsen gets the better of a 22-shot rally to gain the mini break.

He can't make it count as next point on serve the American puts a volley into the net.

Alex Michelsen comes into the net and at 6ft 4in it's a big frame for Alex de Minaur to get past.

De Minaur comes back from being 0-15 down, securing the hold with a deft backhand across court.

He celebrates with a fist pump and we're heading to a tie-break.

Unforced errors have crept into Alex de Minaur's game, prompting concerned expressions on the faces of his coaching team.

Alex Michelsen holds to nudge ahead in a set for the first time in this match.

De Minaur to serve to stay in the second set.

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

Impressive stuff here from the American to fight back.

I love Michelsen's attitude and I think that is one of the things that bodes well if you are looking at his potential.

The way that he has fought back, despite having such a tough start and it all really being one-way traffic, has been really hard. He is showing that resilience.

This is why his attitude to the game is so attractive to get behind as a fan, even the Australian crowd are getting behind him a bit!

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Alex de Minaur skews a forehand wide and all of a sudden Alex Michelsen has a chance to break back.

Australia's De Minaur then double faults and we're all square in the second set!

The noise levels have just gone down a notch in Rod Laver Arena.

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

It was interesting to see De Minaur actually going for the slice a couple of times there.

That tells me that he feels like Michelsen is finding his range because, early on in this match, he was very content to just go blow for blow with him and not change up the spins.

You usually find a player changes up their spins when their opponent is catching rhythm, so definitely something to pay attention to.

A fine forehand winner across court from Alex de Minaur prompts a few claps in congratulations from Alex Michelsen.

Michelsen then opts to serve and volley - and does it to perfection - as he secures the hold.

Australian eighth seed De Minaur will now serve for a two-set lead.

Alex de Minaur has been so good at making Alex Michelsen change direction and the American is off-balance again and unable to get the ball in play.

De Minaur holds and is one game away from taking a two-set lead.

Image source, Getty Images

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

Alex de Minaur is just so quick. Every time he misses the ball, it is a very narrow miss. They aren't big misses at all.

I can imagine that if you are Alex Michelsen, you are holding your breath as you watch each ball go past you.

Alex Michelsen speeds through his service game to hold to love.

He's getting a lot of love from the fans in Melbourne, despite being up against home favourite Alex de Minaur.

Alex De Minaur holds as Alex Michelsen drags a forehand wide.

The American is playing much better now and De Minaur recognises it as he lets out a giant roar in celebration at coming through a tough service game.

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.

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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.