Tokyo, Sep 22 (IANS): Reigning champion Naomi Osaka withdrew from the Toray Pan Pacific Open ahead of her second-round match against No.16 Beatriz Haddad Maia due to illness.

Haddad Maia advanced to the quarterfinals by walkover and will face No.4 seed Veronika Kudermetova, who dispatched qualifier Fernanda Contreras Gomez 6-0, 6-1 in just 56 minutes.

"I am really sorry that I am not able to compete today," Osaka said in a statement.

"It's an honour to be able to play at the Toray Pan Pacific Open in front of the amazing fans here in Japan. This has and always will be a special tournament for me and I wish I could have stepped on court today, but my body won't let me. Thank you for all your support this week and I will see you next year."

A champion in 2019 when the tournament was temporarily held in Osaka, the former No.1 advanced to the second round this year after Daria Saville was forced to retire in the first round due to knee injury.

Osaka's withdrawal was a tough turn of events for the four-time champion. Prior to the tournament, Osaka told reporters that she felt fit and healthy again after her injury-plagued season.

"I think of course the year has been not the best year for me but I think overall I've learned a lot about myself," Osaka told reporters before the tournament.

"I'm happy to be healthy because in Europe I did injure myself and that was the first injury that took me that long to get healed.

"I think life is ups and downs and this one was more down than up but overall I'm happy with where I am right now."