The Malaysian shuttler recorded his third straight-sets victory in succession, defeating Kai Guo 21-17, 22-20.
Chou Tien Chen, the top seed in the men's singles division, eased past 14th seed Ajay Jayaram of India 21-18, 21-19.
Third seed Hans-Kristian Vittinghus booked his spot in the last eight, as did Takuma Ueda, Kenta Nishimoto, Ng Ka Long Angus and Sai Praneeth.
There was disappointment for the home support in the women's singles, with American Beiwen Zhang beaten 21-19, 21-14 by Sayaka Sato.
Top seed Nozomi Okuhara and second seed Akane Yamaguchi who recorded comfortable victories.