Malaysia endured a challenging start to its Japan Open campaign, with three representatives advancing to the Round of 16 in Tokyo.

The sole men's singles representative, Leong Jun Hao, recorded a straight-sets upset over Chinese Taipei's world No. 19 Chi Yu Jen (21-19, 21-16).

Debutants Chen Tang Jie and Clarissa San, however, bowed out in the opening round against Chinese Taipei's Yang Po Hsuan and Hu Ling Fang (15-21, 19-21).

Another mixed doubles pair, Wong Tien Ci and Lim Chiew Sien, also exited after a 34-minute defeat to China's world No. 6 pair Guo Xin Wa and Chen Fang Hui (13-21, 18-21).

Meanwhile, Wong Ling Ching's search for a first win over India's P. V. Sindhu continued after a 14-21, 11-21 defeat in their third meeting, extending the head-to-head record to 0-3.

In the men's doubles, Arif Junaidi and Yap Roy King fell to American pair Chen Zhi Yi and Presley Smith in a gripping three-game contest (24-26, 21-15, 18-21).

World No. 5 pair Pearly Tan and M. Thinaah suffered an upset defeat to Chinese Taipei's Hsu Yin Hui and Lin Jhih Yun despite taking the opening game, going down 21-9, 17-21, 17-21. It was Pearly's first tournament in three months following her recovery from injury.

The same fate befell Ong Xin Yee and Carmen Ting, who lost to Korea's world No. 3 pair Baek Ha Na and Lee So Hee (12-21, 18-21).

Fifth seeds Goh Sze Fei and Nur Izzuddin Rumsani displayed their experience to overcome China's Hu Ke Yuan and Lin Xiang Yi (22-20, 21-18).

Meanwhile, Aaron Tai and Kang Khai Xing produced one of the biggest upsets of the opening round, defeating China's world No. 8 pair Chen Bo Yang and Liu Yi in a thrilling three-game encounter (11-21, 26-24, 21-15).