Fourth seeds Tomokazu Harimoto of Japan and China's Zhu Yuling were eliminated from the men's and women's singles events respectively on the opening day of the International Table Tennis Federation Australian Open in Geelong.
Harimoto's miserable recent run of form continued as he was stunned by China's Wang Chuqin for the second time in the space of a week.
The Japanese player, who had been beaten by Wang in the quarter-finals of last week's Korea Open, lost 12-10, 11-6, 11-4, 11-6 to his Chinese opponent in the ITTF World Tour Platinum event at Geelong Arena.
Wang will face England's Liam Pitchford, an 11-7, 9-11, 16-14, 11-8, 9-11, 11-8 victor over South Korea's Cho Dae-song, in the next round.
Zhu, seeded fourth in the women's competition, also fell at the first hurdle as she was stunned by world number 122 and compatriot Sun Mingyang.
Sun recorded an impressive 11-9, 11-8, 7-11, 11-7, 11-8 victory over Zhu to set up a meeting with Yui Hamamoto of Austria.
Men's singles top seed Fan Zhendong survived a scare as he needed seven games to get past Sweden's Kristian Karlsson 11-6, 8-11, 11-1, 8-11, 11-1, 9-11, 11-6.
World number one Xu Xin is also through after he beat Darko Jorgic of Slovenia 11-9, 8-11, 11-7, 11-6, 11-9.
In the women's tournament, top seed and Korea Open winner Chen Meng was in ruthless form as she dispatched Chen Szu-Yu of Chinese Taipei 11-7, 11-8, 11-7, 11-7 to reach the last 16.
The competition continues tomorrow.