Easy win for Stosur
Top seed Sam Stosur brushed aside home favourite Erika Sema 6-4 6-2 in the first round of the the HP Open in Osaka.
The Australian broke twice in each set to close out victory in one hour 16 minutes.
There was a shock for third-seeded American Christina McHale, though, as she was beaten by Chang Kai-chen of Chinese Taipei.
Chang claimed a 6-3 7-6 (7/5) win in little under two hours in a match which featured nine breaks of serve.
Britain's Heather Watson made an encouraging start with a 6-4 6-4 win over Slovenia's Polona Hercog.
American Jamie Hampton saw off Japan's Ayumi Morita 6-3 6-2 and Australia's Casey Dellacqua defeated another home player in Kimiko Date-Krumm 6-3 3-6 6-4.
Misaki Doi gave the Japanese fans reason to cheer with a 7-5 3-6 6-0 success over Julia Cohen of the United States, while Pauline Parmentier won her all-French clash with Mathilde Johansson 6-2 6-2.