Samantha Stosur has suffered a three-set defeat in her long-awaited comeback from injury at the Japan Open on Wednesday.
Australia's 2011 US Open champion went down 3-6 7-5 6-1 to Spaniard Sara Sorribes Tormo in the first round of the Japan Open in Tokyo.
Stosur, the fifth seed in Tokyo, hasn't played since suffering a stress fracture in her right hand during a fourth-round loss to eventual Roland Garros champion Jelena Ostapenko.
Jana Fett advanced to the second round by beating top-seeded Kristina Mladenovic 6-4 6-3.
Frenchwoman Mladenovic rallied briefly by winning three games in the second set before the 20-year-old qualifier from Croatia served out the victory.
Defending champion Christina McHale of the United States, second-seeded Zhang Shuai of China, local hope Kurumi Nara and Zarina Diyas also advanced to round two.
In second-round action, Belgian third seed Elise Mertens defeated Magda Linette 6-1 7-5, Japan's Miyu Kato upset fourth-seeded Czech Kristyna Pliskova 7-5 6-3 and Aleksandra Krunic of Serbia was too good for American seventh seed Alison Riske 6-3 6-4.
