MELBOURNE (REUTERS)

Two-time champion Naomi Osaka pulled out of the Australian Open with an abdominal injury ahead of her third-round clash on Saturday, saying "it breaks my heart".

The Japanese superstar made the announcement just hours before she was due to meet Australian qualifier Maddison Inglis on centre court in Melbourne.

"I've had to make the difficult decision to withdraw to address something my body needs attention for after my last match," said the 16th seed on Instagram.

"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 can't risk doing any further damage so I can get back on court."

The four-time major champion, who won the Australian Open in 2019 and 2021, said in later remarks to the media that it was an injury she had suffered from "a couple of times before".

"I thought I could push through it. I played my last match with some pain, and I thought maybe if I gave myself a break before my match today, I would be able to handle it. But I warmed up and it got a lot worse."

The 28-year-old mother of one said she needed to see a doctor for more tests.

"Obviously I think coming back from pregnancy, my body changed quite a lot. So this is something I have to be really cautious of," she said.

Osaka left a huge mark on the tournament, going viral when she emerged onto Rod Laver Arena for her first-round match decked out in an audacious "jellyfish-inspired" outfit.

Her white umbrella, matching wide-brimmed hat and long gauzy veil was complemented by a sleeveless turquoise dress over pleated white trousers.

Elsewhere, Madison Keys and Jessica Pegula's podcast will have extra spice after they set up a fourth-round clash.

Keys and Pegula launched The Player's Box last year along with fellow American players Jennifer Brady and Desirae Krawczyk to shed light on life behind the scenes on tour. And listeners will now get a close-up view of how friendship and rivalry collide, with defending champion Keys saying after a 6-3, 6-3 win over Karolina Pliskova: "I think we have to film a podcast before we play the match, so we'll see how that goes."

Keys revealed in her press conference that they have already discussed forfeits for the loser of Monday's clash.

They have played three times before, including in the fourth round of the US Open in 2023, and Keys has no concerns that the contest will affect their friendship.

"We've been doing it for so long," she said. "We could literally be friends and laughing until the moment we walk on the court. Then in that moment we both want to win and we both are competitors. We're going to do whatever we can to get the W.

"The moment it's over, you're back to being friends. I think that's one of those things that I actually really love about tennis, because it's taught a lot of us how to manage our friendships and relationships and be able to genuinely love each other and are close and all of that, but also still be really competitive."

Sixth seed Pegula continued her stroll through the draw with a 6-3, 6-2 victory over Oksana Selekhmeteva while fourth seed Amanda Anisimova became the fifth American woman through to the last 16, beating countrywoman Peyton Stearns 6-1 6-4.