Defending champion Naomi Osaka powers past Marie Bouzkova 6-2, 6-4 to start her Australian Open campaign in style. Osaka was too good for her Czech opponent, taking the first set in 36 minutes after a wobbly start in windy conditions. The second set was a slightly tighter affair as an unforced error from Osaka saw Bouzkova take a vital break to go 4-2 up, but the number 3 seed quickly recovered and secured a crucial break at 4-4 before serving out the match. Osaka's opening day victory makes it 15 wins in her last 16 matches. The reigning champion will now face Chinese world number 41 Saisai Zheng in the second round, who needed just 72 minutes to beat Russian qualifier Anna Kalinskaya 6-3 6-2. Osaka fired back at a social media user who jeered her arrival on court before her victory. Osaka, who admitted to some nerves entering the tournament as defending champion, was less than impressed with one social media user who wrote "Boooooooooooo" on the event's official Twitter page as it announced the match was about to start. Osaka responded after the match with a tweet of her own, asking, "are you big mad or little mad?", then told reporters she could not understand why someone would attack her for no apparent reason. "She was hating. What would her children think? You're just going to come on the Internet and boo me for no reason? I didn't do anything to you," Osaka said when asked about the exchange. " She was very upset. I also wonder, people like this, if they see you in person, I wonder what they would do?"