Osaka - Top-seeded Sam Stosur began the defence of her Japan Women's Open title with a straight-sets victory against Misa Eguchi of Japan on Tuesday.
Coming off a semifinals run in the China Open last week, Stosur defeated Eguchi 6-4, 7-5.
The two-time Japan champion lined up fellow Australian Jarmila Gajdosova in the second round. Gajdosova has a 2-0 record against Stosur.
The three other seeds in action also won; No. 4 Coco Vandeweghe beat Kristina Mladenovic of France 6-2, 6-3, No. 5 Zarina Diyas of Kazakhstan topped qualifier Chan Yung-jan of Taiwan 7-6 (3), 6-1, and No. 8 Lauren Davis of the United States beat qualifier Hiroko Kuwata of Japan 1-6, 6-4, 7-6 (3).