Naomi Osaka moved into the Australian Open second round with a straight-sets victory over Camila Osorio on Monday.

The defending champion was largely untroubled by 20-year-old Colombian Osorio, easing to a 6-3 6-3 victory in 68 minutes on Rod Laver Arena.

Osaka, a four-time grand slam winner, has now won 23 of her past 24 matches in Melbourne.

It means a fourth-round showdown between Osaka and world number one Ash Barty remains on the cards.

Osaka made an imperious start and raced into a 5-0 lead after 16 minutes, on the back of eight winners, plus seven unforced errors from Osorio.

Incredibly, Osorio – who was growing in belief – had chances to get back on serve when Osaka was trying to close out the set, but the two-time champion in Melbourne managed to seal it 6-3.

The energetic Osorio was encouraging herself throughout while matching Osaka, who broke for a 2-1 lead in the second set.

In the end, Osaka proved too good despite a decent first-round test, moving into a meeting with either Dayana Yastremska or Madison Brengle.

DATA SLAM: Osaka's first-round record remains strong

Osaka is rarely troubled in the opening round of grand slams. The star is now 19-2 in the first round at majors.

Another challenge awaits. Osaka has never defended any of her major crowns and the last player to defend the women's title at Melbourne Park was Victoria Azarenka (2012 and 2013).

WINNERS/UNFORCED ERRORS
Osaka – 19/28
Osorio – 5/15

ACES/DOUBLE FAULTS
Osaka – 4/3
Osorio – 1/4

BREAK POINTS WON
Osaka – 4/6
Osorio – 1/5