Andreas Seppi is still fighting. He just misses with a forehand to the right though and it is 15-15.

The Italian goes for another big winner but his forehand cross court just misses.

A brilliant pass down the line from Seppi gets the thumbs up from a helpless Djokovic at the net but the Serb responds with a sliced ace to set up set point.

The world number one wastes that with a double fault but he doesn't let that bother him as he wins the next two points and the set.

What a reception for Nick Kyrgios.

The Australian walks on court and the Aussie flags are flying,

This could be explosive.

Trouble for Andreas Seppi as he nets at 5-5 to go down 15-30.

Mini crisis averted with a forehand winner onto the tramline, but, after a punishing baseline rally, the Italian nets and a break point Djokovic.

He's done it. Djokovic punches the air after the rally of the match. Great defence from Seppi to reach a drop shot but the rally goes on and the Serb's power eventually forces Seppi into the net.

Djokovic serving for the set.

Next up on Rad Laver Arena is a tasty-looking encounter.

Australia's new hope Nick Kyrgios against Czech sixth seed Tomas Berdych.

This one should be a classic. They will be on court soon.

Serena Williams: I think I played well. Everything I did went right.

"I have so many memories of being 18, Daria has such a bright future, she is so young.

"Her team is doing an amazing job and she is heading in the right direction."

Williams on her yellow outfit: "It is not built for warmth, it is built for speed."

A warm embrace at the net.

Daria Kasatkina was given a lesson there but that can only be good for the 18-year-old in the future.

Can anyone stop Williams lifting this title? It would take some performance.

Ace number six for Williams as she opens the game in style.

A big, big backhand makes it 30-0 before some neat footwork allows Williams to wrong foot Kasatkina with another forehand winner.

Game Williams as she advances to the net and volleys away. 

Seppi picks up his game - he's holding his serve well and nearly broke Djokovic. Nearly's not enough though, Andreas.  

Image source, ap

Unstoppable.

Serena Williams is barely dropping points.

This time the American breaks to love.

The end is nigh.

Image source, AFP

Serena Williams does not look like having her serve broken.

She has virtually 80% first serve accuracy and has lost two points on serve all match so far.

A driven forehand cross court wins another game to love.

That is just showing off. A driven volley from mid court gives Williams the opening point.

Kasatkina shows some guts, going for a big second serve, and it pays off as Williams can't get the return over the net.

The Russian wins the next two points but an overhead from Williams brings it back to 40-30. Deuce, as a very short second serve is hammered away cross court for a winner.

Another service return winner and another break point. Saved. Williams then goes long, then wide and game to the Russian.

Wow.

You have to feel sorry for Daria Kasatkina. She is getting totally blown away.

Another impeccable service game won to love.

Image source, AP

Well played Kasatkina. An angled forehand from behiind the baseline makes it 15-15.

15-30 though as a wide serve is hammered away for a winner by Williams, who follows that with a cross court backhand winner.

Kasatkina is long and another break for Williams.

This is a serving exhibition from Serena Williams.

A couple more aces, a booming first serve that Kasatkina can't return and we have three set points.

No mistake, Williams powers away a forehand for the first set. Brilliant.

Image source, afp

"NO!" shouts Djokovic, as he angrily reacts to losing a point during his service game. 

Play is then delayed temporarily as someone appears to fall ill in the crowd. The umpire stops plays to make sure all is well - and we continue.  

Daria Kasatkina is doing okay.

She is staying in a few rallies with Williams but, ultimately, she just doesn't have the capability to mix it with the American.

The Russian gets to 30-30 but another break point for Williams as Kasatkina races to get hold of a drop shot but can only slice into the net.

Another double fault and another break.