Australian Open, day nine AS IT HAPPENED: 'More to prove': Sinner awaits challenge from American star; 'Anxious' Ruud troubled by 'unpredictable' rival

Day nine is done and dusted, but the Australian Open action is not over yet!

Thank you for joining us for all the action today. We will be back tomorrow for more.

Novak Djokovic was supposed to be the man to take to the court on Rod Laver Arena this evening, but his fourth round match was cancelled due to a late withdrawal by his opponent.

That withdrawal meant he walked straight into the quarter finals and Ben Shelton's battle against Casper Ruud was moved onto Rod Laver Arena.

"I know you guys were probably looking forward to watching Novak tonight," Shelton said, as a chorus of boos began to echo around the stadium.

Those boos were quick to stop, though, as he continued to speak.

"But I hope we didn't disappoint you with that match tonight," he ended.

Shelton's next challenge will be against the world No.2 Jannik Sinner.

He is not hiding his confidence heading into that match.

"It's what you look forward to the most in this sport," Shelton said.

"It's where I wanted to to here. I wanted to give myself another shot on some things that I did well last year and leave it all out on the court.

"I have a lot more that I want to do here and I have a lot more to prove, so I hope you guys come back in two days time because I'll be ready to go."

Jannik Sinner's quarter final opponent has been locked in. It is Ben Shelton.

The American star was just too dominant in the final two sets against Casper Ruud, eventually winning the match 3-6, 6-4, 6-3, 6-4.

While it is not the ending Ruud was hoping for, it does mean that he will be in no rush to get back to Norway for the birth of his first child, a daughter.

Ruud's wife Maria is heavily pregnant and the star tennis player has made it clear that he would depart the tournament at any stage if she went into labour.

There has not been a more clearer issue for Casper Ruud in this match than his forehand shots in the middle of a rally with Ben Shelton.

Ruud is typically one of the stronger athletes on the tour when it comes to delivering such shots, but this evening, things are not quite going to plan.

"You're not going to find more of a fan of Casper Ruud probably than me," Jim Courier admitted in commentary on Nine.

"I love his forehand so much, but that forehand has failed him twice on the biggest points of the match when he was serving.

"I mean, those are anxious forehands. That's nerves interfering with play.

"He's in real trouble here."

Lleyton Hewitt added.: "It has turned quickly in the last couple of minutes.

"(Ruud) has made a couple of bad errors under pressure. He's self destructed a little bit."

Shelton has won the third set 6-3.

Just like that, the scores are level.

Ben Shelton has claimed the second set with a dominant display, 6-4.

It has been a long-hitting, fast-paced match so far. Shelton is moving further and further behind the Melbourne logo on the court, as is Casper Ruud, to make their shots.

The fans in the stands at Rod Laver Arena are nothing short of entertained.

A $480,000 cheque will be heading in the direction of Maddison Inglis' bank account in the coming days, following what has been a remarkable dream run at the Australian Open.

Inglis has not hidden the fact that she would not have believed you just over a week ago if you told her this would be her reality, yet here she is.

In fact, it is the most prize money she has ever won in a tournament.

So how exactly does she plan to use her winnings?

"I'll definitely use a lot of it to invest back into my tennis ," she revealed.

"And have some people on the road with me to support me, and make some weeks a bit easier with family or friends because it's a long year."

"I love shopping," she added, laughing.

"So I'm sure I'll buy something nice. I've wanted a Smeg toaster for so long, so long that I just was like, 'no you can't do that'. I think that's going to be my treat and maybe the kettle, too."

Things are beginning to heat up on Rod Laver Arena.

Casper Ruud has been in control for most of the match, although he has had to push through some long rallies and remarkable returns from his American opponent.

Ben Shelton looks calm despite trailling on the scoreboard. So much so, he has put the first-set loss behind him and come back firing to open the second set.

As we near closer to the one-hour mark, Shelton leads the set 3-2.

"He is finally settling into this match," Todd Woodbridge said of Shelton on Nine.

American star Amanda Anisimova admits it has become "pretty difficult" dealing with online criticism after she reached the Australian Open quarter finals.

The world No.4 has been operating at an incredibly high level at the first grand slam of the year and is yet to drop a set in her four matches to date.

Anisimova will now move into an all-American clash with Jessica Pegula, which should have been the main talking point for her at Melbourne Park.

However, there has been plenty of reaction and attention surrounding Anisimova following her press conference earlier in the tournament.

When asked about representing the USA amid the country's current political climate, she quickly shut the line of questioning down and brushed it off.

"I don't think that's relevant," she said.