US Open champion and fourth seed Osaka was too good in her 6-2 6-4 victory over Zidansek in humid conditions at Melbourne Park on Thursday.

Osaka – aiming to become the first woman to win successive grand slams since Serena Williams claimed the 2014 US Open followed by the Australian Open, French Open and Wimbledon in 2015 – will face Hsieh Su-wei in the next round.

Japanese star Osaka stormed out of the blocks after a brief rain shower delayed the start of the match as the Margaret Court Arena roof was closed.

Osaka, who has never reached the quarter-finals in Melbourne, earned three break-point opportunities in the opening game and converted the third with a cheeky drop-shot winner, much to the delight of the pro-Osaka crowd.

A couple of loose errors saw Osaka broken back, but the crowd favourite reclaimed the break immediately after sensationally guessing the direction of Zidansek's smash before consolidating for a 4-2 lead.

Another break in the seventh game capped a fine first set for Osaka, one of eight winners in an impressive 28-minute opener against the Slovenian.

Zidansek was not overawed, however, as she continued to go toe-to-toe with the Japanese star, breaking at 30-40 for a 4-2 lead.

But just as Zidansek seemed to have the momentum, Osaka regained her composure and the break to move past the second round.

STATISTICAL BREAKDOWN 
Osaka [4] bt Zidansek 6-2 6-4

WINNERS/UNFORCED ERRORS 
Osaka - 17/23
Zidansek - 13/26

ACES/DOUBLE FAULTS 
​Osaka - 6/1
Zidansek - 2/2

BREAK POINTS WON 
​Osaka - 5/13
Zidansek - 2/5

FIRST SERVE PERCENTAGE 
​Osaka - 66
Zidansek - 64

PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE 
​Osaka - 79/47
Zidansek - 45/52

TOTAL POINTS 
​Osaka - 65
Zidansek - 44