Naomi Osaka suffered a disappointing end to what has been an encouraging Australian Open, as she retired with an abdominal injury after losing the first set against Belinda Bencic.

The Japanese star came into the event nursing the problem after pulling out during the final in Auckland last weekend but impressed in victories over Caroline Garcia and Karolina Muchova.

Osaka led 5-3 in the opening set and had the chance to serve it out, but was broken and went on to lose the tie-break as Bencic won the set in 58 minutes.

That proved to be the end of the match, with Osaka trudging over to Bencic to bring an end to the match.

"It was a little hectic trying to manage it, because obviously my draw was quite tough," said Osaka.

"But we were also doing everything we could, I was going to therapy every day and stuff like that into the night. After my last match, it got way worse. It was just, I guess, a little inevitable, but I think the competitor in me just wanted to see it through until the end."

It was the first time the 27-year-old had made it to the third round of a Grand Slam since returning from the birth of daughter Shai in 2023.

"I feel like the positives is why I'm negative, because I feel like, if I could have served, then I could have potentially won, and I could have maybe gone far in the tournament," said Osaka.

"I was in the final in Auckland, too, and it sucks because I also think I could have maybe won that tournament and it could have been my first tournament win back."