Japan's Naomi Osaka celebrates after defeating Marie Bouzkova of the Czech Republic in her opening match at the Australia Open. Photo: Lee Jin-man/AP Photo

MELBOURNE  Defending champion Naomi Osaka overcame a patchy and error-prone performance to advance to the second round of the Australian Open on Monday with a 6-2 6-4 victory over Czech Marie Bouzkova.

The 22-year-old Japanese next faces China's Zheng Saisai, who needed just 72 minutes to beat Russian qualifier Anna Kalinskaya 6-3 6-2.

Third seed Osaka struggled in the opening exchanges but broke the 21-year-old Bouzkova twice in the first set, which she clinched with a forehand winner in 36 minutes.

The pair battled with swirling winds on Rod Laver Arena and Bouzkova managed to break in the sixth game of the second set but Osaka, who relied on a big serve and booming ground strokes to get out of trouble, broke back twice again and sealed victory when the Czech sent a backhand wide after 80 minutes.

Meanwhile, Seven-times Australian Open champion Serena Williams looked in ominous form as she opened her 19th campaign at Melbourne Park with a 6-0 6-3 trouncing of Anastasia Potapova.

Serena Williams, left, is congratulated by Russia's Anastasia Potapova after winning their first round at the Australian Open. Photo: Lee Jin-man/AP Photo

American Williams, 38, arrived at the year's first Grand Slam having won her first WTA title in three years and made short work of the out-gunned Russian teenager on Rod Laver Arena.

A clean crosscourt winner gave the eighth seed the first set in under 20 minutes and although former Wimbledon junior champion Potapova made her fight harder in the second the match was wrapped up inside an hour.

Williams will play Slovenia's Tamara Zidansek or South Korean wildcard Han Na-lae in the second round as she continues her quest to match Margaret Court's record career tally of 24 Grand Slam singles titles.