Good sportsmanship from Carlos Alcaraz there.

Alex de Minaur gets a time warning for taking too long over his serve, but the world number one stands up for him, saying "I wasn't ready".

Image source, Getty Images

Alex de Minaur holds his hand out, pointing at the huge gap that he could have sent a winner into instead of batting cross-court and wide.

Carlos Alcaraz fizzes a sublime winner past the Australian, and then - after failing to catch De Minaur out with a drop shot - he rushes to the net and slams down another cheeky winner.

He walks away from that game with a big grin.

Carlos Alcaraz misses, ties his shoelace, then misses again.

All square in this first set. Are we heading for a tie-break?

Alex de Minaur isn't out of the woods just yet. Another miss brings us to deuce.

A groan from the crowd as Alex de Minaur sends the ball out despite having more room to aim for the other way.

The ball sits up nicely for the Australian on the next point, though, and De Minaur takes his time to line up his shot before slamming it down the line. 30-15.

Image source, Getty Images

Jonathan Jurejko
BBC Sport tennis news reporter in Melbourne

Aussie confidence feels quite fragile - both on the court and in the stands.

De Minaur is fluctuating from staying in his shell and showing spurts of belief.

The home crowd are doing the same. It doesn’t feel like they truly think De Minaur can sustain a good enough level to beat Alcaraz over five sets.

But, if he fights back again and wins the opener, that should send optimism soaring.

Alex de Minaur can't win the first break point, but he makes up for it with a brilliant forehand down the line on the next one.

The Australian stays alive in this first set.

Carlos Alcaraz pulls out the drop shot but Alex de Minaur is speedy enough to get there and the Spaniard is forced to duck out of his way as he hammers the ball back. 15-40.

Two break-back points.

Alex de Minaur isn't letting this opening set slip away just let as he opens up a 0-30 lead on Carlos Alcaraz's serve.

Pat Cash
Former Wimbledon champion on BBC Radio 5 Sports Extra

There is not too many players who can change their game style in the middle of a set or even in the middle of a game, but Alcaraz is one of them. That is probably why most people have picked him [to win].

He is smashing the ball backwards and forwards, playing De Minaur's game - it has been trouble for every player so far in this tournament.

I think De Minaur will adjust.

An overcooked forehand from Alex de Minaur silences the crowd on Rod Laver Arena, while Carlos Alcaraz shouts "YES!"

He'll serve for the set now.

A big chance here for Carlos Alcaraz. Three misses from Alex de Minaur give him three opportunities to break and serve for the set.

Carlos Alcaraz drags Alex de Minaur wide with his first serve and then unleashes a huge cross-court winner which the sixth seed has no hope of getting to.

And there's the hold as De Minaur fires long.

Alex de Minaur looks over to his team and lets out a sigh of frustration after firing two points wide.

Then there's a huge cry of "vamos!" from Carlos Alcaraz as he pulls a point clear. But another backhand into the net brings us to deuce.

Image source, Getty Images

Pat Cash
Former Wimbledon champion on BBC Radio 5 Sports Extra

Alcaraz is making a lot of unforced errors, 11 compared to De Minaur's two.

That's the way he plays - he doesn't make many mistakes and gets everything back.

Carlos Alcaraz loops a forehand long and it opens up a half-chance for Alex de Minaur on the Spaniard's serve. 0-30.

The brilliant points keep on coming, with Alex de Minaur winning the next two and hitting his first winner in the process.

Carlos Alcaraz pushes the ball into the net again and that's three games in a row for the Australian.

That would have been impressive from Alex de Minaur. He bats away a couple of forehands at the net before Carlos Alcaraz goes for the lob. It pinches the baseline but somehow, De Minaur gets there and he whacks it back Alcaraz's way - only for it to fall a couple of centimetres beyond the baseline. 15-15.

Image source, Reuters

This time he gets it. Carlos Alcaraz plants a backhand into the net and we're back on serve in this opening set.

Alex de Minaur can't make the most of Carlos Alcaraz's second serve and sends the first break point into the net.

He does the exact same thing on the second. One left...