Naomi Osaka withdrew from the Pan Pacific Open due to abdominal pain on Thursday afternoon.
Osaka won her first-round match against Daria Saville on Tuesday night when the Australian suffered an ACL tear during the first set. She was due to face Brazil's Beatriz Haddad Maia in the second round on Thursday night.
“I am really sorry that I am not able to compete today," Osaka said in a statement released by the tournament. "It’s an honour to be able to play at the Toray Pan Pacific Open in front of the amazing fans here in Japan.