revealed she has suffered abdominal problems since she was a teenager as the two-time champion was forced to pull out of the .

The former world No.1 retired in tears from the final of the Auckland Open with the stomach injury after winning the first set earlier this month.

This time Osaka, 27, lost a first-set tiebreak against fellow mother Belinda Bencic but she was unable to carry on because of the same injury. Reaching the third round here had been her best Grand Slam performance since she gave birth to daughter Shai in 2023.

The Japanese star said: "It's not fantastic, and I'm not great, not bad. In the middle somewhere. It was a little hectic trying to manage it, because obviously my draw was quite tough.

"But we were also doing everything we could, like I was going to therapy every day and stuff like that into the night. So the days have been very long for me. I kind of have a history of it since I was a teenager. At least once a year I'd get an ab strain.

"It's more like the way my serve is. Like, it's quite explosive. When I think about last year, I didn't get an ab strain in the middle of the season. It was more towards the end, like Beijing.

"So in a weird way I'm kind of proud of that. Unfortunately, it carried on to the beginning of this season, but hopefully I can get it together in time for the U.S. swing."

Playing in her first Grand Slam since giving birth to her daughter Bella, Bencic drew a heart on the lens of a courtside TV camera and wrote: "Get well soon Mama."

The Swiss world No.294 will now face Coco Gauff after the American beat Leylah Fernandez 6-4 6-2. The world No.3 has yet to drop a set this year.