Great Britain's Paul Drinkhall and Joanna Parker lost their opening singles matches at the Olympic test event at London's Excel Centre.
Drinkhall lost 4-1 to China's former world champion Wang Hao in the last 16 at the ITTF Pro Tour Grand Finals.
Parker had a daunting task against current world champion Ding Ning, with the Chinese player coming through 4-0.
Darius Knight lost to Singapore's Chen Feng, Hung Tzu-Hsiang of Taiwan and top seed Kim Min Seo in the under-21 event.
British hopefuls Liam Pitchford and Andrew Baggaley have still to play in the doubles, although they have been drawn against number one seeds Ma Lin and Zhang Jike.
The end-of-season tournament will include a Great Britain v Rest of the World match on Friday evening.