Naomi Osaka's second-round match at the Australian Open could not possibly have started in a worse way. All of 21 minutes in, she sailed a forehand service return well long and, just like that, trailed 5-0.

After losing the first set 7-6 (3), two-time Australian Open champ Naomi Osaka retired from her third-round match against Belinda Bencic due to injury.

Two-time Australian Open champion Naomi Osaka said "it sucks" after retiring Friday with a stomach muscle injury during her third-round match against Belinda Bencic in Melbourne.