Victories over the leading names in their groups earned respective progression for Payas Jain of India, Nicolas Burgos of Chile, Tomas Martinko of the Czech Republic and Poland’s Maciej Kubik.

In the girls' singles, Romania's Elena Zaharia and Chinese Taipei’s Lee Wan-Hsuan produced outstanding performances.

Jain accounted for Belgium’s Adrien Rassenfosse 11-13, 11-7, 11-4, 7-11, 7-11, 11-6, 11-6; Burgos beat Chinese Taipei's Huang Yan-Cheng 11-6, 11-8, 12-10, 5-11, 5-11, 11-8; and Martinko ended the hopes of New Zealand's Nathan Xu 11-6, 11-8, 11-9, 11-9.

Kubik earned the single qualifying spot in his group by beating India's Raegan Albuquerque 11-9, 11-5, 9-11, 6-11, 13-11, 11-3.

Singapore's Beh Kun Ting, who the previous day had beaten Germany's Kay Stumper, the leading name in his group, continued his good form as he overcame Chile's Sebastian Gonzalez 11-2, 12-10, 11-8, 11-4 to reserve his main-draw place.

The girls' singles produced even more upsets - and Zaharia and Lee were prime contestants.

Zaharia beat Hong Kong's Lee Ka Yee 11-9, 11-8, 11-6, 22-20, while Lee defeated Germany's Franziska Schreiner 12-14, 11-4, 11-4, 11-8, 11-9.

Crystal Wang of the United States, Camille Lutz of France and Poland's Aleksandra Michalak, alongside Japan's Kyoka Idesawa and Hong Kong's Fung Wai Chu, all ended qualifying unbeaten.

Similarly, the North Korea trio comprising Kim Kum Yong, Kim Un Song and Pyon Song Gyong also completed their matches without defeat.