Defending champion Naomi Osaka posted a relatively trouble-free 6-3, 6-3 victory over Camila Osorio in the first round of the Australian Open, while 18th-seeded American Coco Gauff was upset by China's Wang Qiang 6-4, 6-2.

Osaka wins Aussie opener; Gauff upset by Wang

Defending champion Naomi Osaka posted a relatively trouble-free 6-3, 6-3 victory over Camila Osorio in the first round of the Australian Open, while 18th-seeded American Coco Gauff was upset by China's Wang Qiang 6-4, 6-2.