Naomi Osaka has now won 19 of her 21 first-round matches at a Grand SlamDates: 17-30 January Venue: Melbourne ParkCoverage: Daily radio commentaries on BBC Radio 5 Live Sports Extra, BBC Sport website and app, with selected live text commentaries online; TV highlights from middle Saturday.Japan's Naomi Osaka opened her defence of the Australian Open title with a dominant win over Colombia's Camila Osorio on day one in Melbourne.
Osaka, also champion in 2019, raced into a 5-0 lead in the first set before world number 50 Osorio fought back.
However, Osaka quickly reasserted her control and wrapped up a 6-3 6-3 win.
After taking a four-month break at the end of last season to protect her mental health, Osaka returns to Grand Slam action as the 13th seed.
"I thought I played pretty well given the circumstances," said Osaka, who has won 23 of her past 24 matches in Melbourne.
"Overall I'm happy to be here and see everyone in the audience.
"I like the hot conditions but when I come here everyone is warm and welcoming. I'm sure that has a positive effect on me."
The four-time Grand Slam champion will play Ukraine's Dayana Yastremska or American Madison Brengle in round two on Wednesday.
