Just hours out from her clash with Australia's Maddison Inglis, Naomi Osaka has pulled out citing injury.

"I've had to make the difficult decision to withdraw to address something my body needs attention for after my last match.

"I was so excited to keep going and this run meant the most to me, so having to stop here breaks my heart but I cant risk doing any further damage. So I can't get back on court.

"Thanks for all the love and support, I'm so grateful everyone embraced me so much."

SEN's Sam Groth broke the news on air shortly before Osaka's announcement.

"Quite extraordinary," he said. "I've got to confirm this, it could be big news here at Melbourne park, but I'm hearing Naomi Osaka is not taking to the court.

"I've had a tip and that is huge news for Inglis and Aussie fans....

"It will be her best slam result (Inglis) and from qualifiers and it's a walkthrough to the fourth round.

"Unconfirmed at this point that Naomi Osaka has withdrawn and that Inglis will not have to play at this point," he said.

What this means is Australia has a woman into the fourth round of the tournament and Inglish is set for a minimum payday of $480,000.

Was the heat rule enacted right?

There was a wry smile from Eliot Spizzirri when the extreme heat policy was called into play on Saturday at the Australian Open. The timing raising plenty of eyebrows at Melbourne Park.

Jannik Sinner was chugging on pickle juice and visibly limited in what he could do as he faced a break point in the third set against his American opponent.

""He is in a bit of trouble here," Todd Woodbridge said on Channel 9 at that point of the match.

"I think he had some pickle juice in that change over but he is cramping, his thumb just went.

"The shoulders, the back they're all going off on strange angles. He can barely walk."

Sinner was struggling while his opponent was barely breaking a sweat. And then it was confirmed by the umpire; the extreme heat policy had been activated as the pressure metre hit 5.0. Play was suspended.

Then came the smirk. Even the commentators noticed and reflected that Spizzirri would be irritated by the decision.

With the roof closed on Rod Laver Arena and the temperature controlled, Sinner was going to get the upper hand.

As Woodbridge conceded, had the policy not been activated for another 10 minutes this story would have had a different ending.

A mandatory break for players in the heat policy, twinned with the time it takes for the roof to close, allowed Sinner the rest he need to close out the match and confirm his place in the fourth round.

No hard feelings according to his opponent who, while irked by the timing, said the rules were there to protect players.

Fans were not so gracious suggesting it was far too coincidental for it to have been called at the exact moment the world No 2 and defending champion struggled. Cue the conspiracy theorists.

"I don’t know if he got saved by it," Spizzirri said hen asked if the timing was a little suspicious. "I smiled a little when the heat rule went into effect because it was funny timing. But the game at 2-1 in the third set hit 5.0 so it was in effect.

"Whether I broke or he held we were closing the roof. Its just funny it happened that way but it’s the rules of the game. You have to live with it. If I won that third set we would have a 10 minute break aways. Who knows We have seen him do this before.

"I wouldn’t say he got saved by it, he is too good of player to do that. You could say he (got lucky) but he handled it well.

"I wasn’t thinking too much about his side of the court. When I saw how hot it was I didn’t feel disappointed in that I tried to relish that and see it as an opportunity to demonstrate my physicality."

In fact, the American was dishing out compliments to Sinner.

Sinner is the biggest name in tennis he had ever played on the biggest court. Spizzirri was nothing but honourable in defeat but did concede he has played in far worse conditions than today's 41 degrees in Melbourne.

"He’s been in gruelling matches. Its not fair for me to say ‘I’ve got him today’," he said.

"I felt good. I was talking to a couple of people, this heat is nothing compared to Florida or what I trained in in Austin. It's dry heat here. I played a match in China last year that was not even ballpark close to today. I felt fresh I would have gone a lot longer.

"I think it's genetic a bit (cramping). I see guys that are maybe saltier sweaters that are more prone to cramping. You have to maybe figure out the right mix of nutrients. I'm up to speed with the cramping.

"Seeing a guy like Sinner struggling with cramps tells you everything. I think it's genetic and experience. Who knows, anyone can cramp in these conditions."

Asked if there were any hard feelings about what could have been, he added: "The rules are the rules, I was just saying I've played and trained in worse conditions.

"Maybe it's a good thing to have under my belt that I have done that but I'm not gonna lie and say I didn't feel it was crazy hot. This rule is protection for us. it will promote guys to stay healthier.

"I'm not gonna say it's a bad rule, it's a great rule but today is not the hottest day ive played in at all."

5:25pm Big two's dominance is "a problem"

Men’s tennis is not in a healthy spot, according to pat Cash who says Carlos Alcaraz and Jannik’s Sinner’s dominance is damaging the sport.

The Spaniard and Italian have won the last eight slams between them and while some may argue it’s a declaration of dominance, a raising of the bar, others (like Cash) say it’s boring.

“It’s not a healthy situation to have a two-horse race,” Cash told the BBC. “There's those two guys, and then there's the others.

“Anything can happen in a long tournament, but a two-horse race is not necessarily healthy for Grand Slam tennis or the tour.

“If there's only two players that everybody's talking about, that's a problem."

Sinner suffered an early scare this afternoon dropping his opening set against America’s Eliot Spizzirri but ultimately won through after the roof was closed and conditions improved exponentially.

GAME SET AND MATCH: SINNER SURVIVES

Well what a turn around and Jannik Sinner has to count his lucky stars for the heat today because he would have been in an ice bath hours ago if they had not shut the roof.

Three match points for the world No 2 to secure his fate. And while he stumbles on the first it's all over 4-6, 6-3, 6-4, 6-4.

"He can count his lucky stars that the heat kept climbing and he could fight off the cramps," Woodbridge said on comms.

"Spirrizzi will feel hard done by and unlucky. If it had been 10-15 minutes later, perhaps Sinner would not be the victor today such is the timing of what occurred.

"But my goodness Sinner is mentally tough to have come through this. The pickle juice, what stuff that is."

Speaking after the win, which incidentally is also Sinner's longest ever match at the Aus Open (that he has won), the Italian said he had been struggling all over his body.

"He is an incredible player. I wish him only the best. I am sure he going to have a great season," Sinner told Colin Fleming. "I struggled physically today.

"I got lucky with the heat rule and the roof closed. I took my time and as it passed, I felt better and better.

"I hope this can give me some positive with the next round.

"Many things. I started with the legs then into the arms, I was cramping all over. This is the sport. This is an area I need to improve.

"At the end of the day, tennis is a mental game. I tried to stay calm. I am here to fight. Not playing at my best I tried to.

"I have a good record indoor, but if I want to go far I need to play in other conditions."

3:46 Sinner is still struggling

He's not anywhere near close to 100% but he has improved significantly since the cramping that almost ended his match.

With every shot being hit on RLA right now the narrative of this match is changing.

Every time Sinner has to stretch for something I fear he is going to tear any one of his muscles, such are the grimaces on his face.

Spizzirri has just broken the world No 2 in the fourth set while trailing by 2 sets to 1.

__PLAY HAS BEEN SUSPENDED

The Australian Open extreme heat policy has been activated and all matches have stopped.

The head umpire has just announced there will be no matches called on outside courts before 5.30pm.

3:18pm the pendulum swings

Well isn't this just a turn of fortune. How coincidental the heat score hit five right when Sinner was cramping to the point we were questioning if he could go on.

Anyway, close the roof, control the heat and he's just won the third set.

Fans on social media have not been quiet about the aforementioned coincidence either.

2:30pm Sinner is struggling in the furnace

The temperature has hit 36 degrees at Melbourne Park but play is yet to be suspended.

World No 2 Jannik Sinner is "in a bit of trouble" on Rod Laver Arena where he has called the trainer and is visibly cramping.

"He is in a bit of trouble here," Todd Woodbridge said on Channel 9. "I think he had some pickle juice in that change over but he is cramping, his thumb just went.

"The shoulders, the back they're all going off on strange angles. He can barely walk."

It's currently a set apiece between sinner and Spizziri.

Once the heat measure hits "5" play will be suspended and the roof will be closed on the show courts. If he can hold on, that will play to Sinner's advantage.

Sinner then took a time violation penalty after taking too long to try and walk the cramps off between serves.

Brutal, brutal conditions.

Sinner's coaching team willing him on every point.

2:05pm Sinner fights back

It's all even on Rod Laver Arena and having just walked back from that court, It is like a furnace!

The heat scale has hit 4.4 which means we're approaching the suspension of play. Remember when we hit five, that's it's for the outer courts.

A big day for Italian tennis with No 15 seed Karen Khachanov just knocked out by Luciano Darderi 7-6 (5), 3-6, 6-3 y 6-4.

Who you ask? Apparently the world NO 25 but I hadn't actually heard of him before now.

What a huge scalp for him!

1:45pm Raducanu told to lift

This year will mark the 6th anniversary of Emma Raducanu’s incredible run to the US Open title.

She was only 18 at the time and it catapulted her into a world of attention, spotlight, commercial and fame that she could never have imagined.

But besides some injury issues and seemingly relentless coaching changes, little of note has happened since.

This week in Melbourne she crashed out of the tournament in the second round and it was former slam champion Andy Roddick that took issue with the Brit’s approach to her craft.

“I read stuff in the off-season, (Raducanu) saying, 'I want to play a little less this year.' Play less? You're a Grand Slam champion who's (ranked) 30 in the world, you've got to play more.

"I want her to want to play more. You don't know all of it but when you have an off-season to train, you should be coming in pretty healthy.

"So Emma saying she wants to play less... Earth wants you to play more. You haven't played a full season.

"It's been five years since the Open. At some point we're going to have to get to it being a job."

1:12pm Sinner in trouble?

If there's one day you want a straight sets win it's today. The heat scale is closing in on 4 which means extended breaks are given to players and Jannik Sinner has just dropped the first set over on Rod Laver Arena Against Eliot Spizzirri.

And it's not started well in the second - the world No 2 broken in the first game.

12:29pm Djokovic hits out at "disrespectful" Osaka

It’s been a week of politics, jellyfish and a few on court tiffs at Melbourne Park and now Mrs Djokovic has entered the fray.

Fresh from Naomi Osaka’s frosty handshake with Sorana Cirstea on Thursday, debate has raged about whether the Japanese star’s midpoint outbursts and noise were appropriate or not.

Cirstea was furious that Osaka has been cheering and psyching herself up between points and when her opponent made a fault.

While not illegal in the sport it does push the boundaries of etiquette.

For Mrs Djokovic however, who lets face it after 20 plus years on the circuit knows the sport fairly well, it was downright disrespectful from Osaka.

“In between 2 serves, when crowds are applauding or shouting, the chair ump asks not to shout between serves as it is disturbing to the player,” Djokovic said on an Instagram post.

“The point is not finished.

“Sorana missed her first serve and is focusing on getting in the second, it is a slight pause. “And it is disrespectful to applaud at someone’s first serve mistake too.

“I am surprised that the chair / Naomi thought that was fair?!

“Were there any rule changes that I missed?!”

Immediately after the win Osaka saw no issue with what she had done but in her press conference an hour later apologised for any disrespect shown.

Heating up and playing fast

Jessica Pegula has secured her spot in fourth round after beating Russia’s Oksana Selekhmeteva 6-3 6-2 in just 66 minutes. Also through to week two is defending champion Madison Keys who beat Karolina Pliskova in straights sets. not gonna lie I totally thought Pliskova had retired

11am Super fan kicked out of the Aus Open

Tennis “super fan” James Bray has had more TV time than some players so far this Australian Open, but he will be off screen for at least 24 hours after being ejected and banned form the tournament.

Bray was courtside to cheer on Aussie Alex de Minaur but his vocal support was deemed more worthy of a $700 fine and a police escort off the premises than simply being an over excited fan.

“Unfortunately I’ve been kicked out of the Australian Open because I’ve been too rowdy,” Bray said in a series of Instagram posts.

“I was cheering him, not disrespectful at all, I wasn’t cheering in between double faults or in between serves.

“I was just cheering him on like I would any Australian on any court and for some reason security came up to me and said ‘sorry mate, you’ve been warned, you need to leave’.

“It was a bit of a weird one, I feel like I wasn’t doing anything bad, everyone around me was cheering.

“If I was doing that same thing at John Cain Arena, no one would have battered an eyelid.

“The people next to me were loving it, Demon was loving. I feel like Tiafoe’s a legend, he loves it too. So I don’t know what the issue was. I’ll be reaching out, I want some answers. I was just doing what everyone else does, having fun, cheering on the boys.”