Mark Philippoussis lost 6-3 6-4 to Czech player Tomas Zib as the rain-hit Japan Open finally got under way.
Philippoussis failed to find his form
Zib humbled the big-hitting Australian at Tokyo's Ariake Colleseum on a day when many matches were postponed.
Other first-round winners included Harel Levy, who beat Lu Yen-hsun and local star Takao Suzuki, who defeated Chile's Adrian Garcia.
Top seed Lleyton Hewitt had a first-round bye, as did Wimbledon champion Maria Sharapova in the women's bracket.