Top seed Anthony Susanto is on course to reach the 48th Brunei International Tennis Federation (ITF) Junior Circuit boy's singles final after beating compatriot Haekal Ramadhan 7-5, 6-3 to move into the last-eight yesterday.
The Indonesian will now meet eighth seed Leo Vithoontien after the Thai went past Indonesian 12th seed Pambudi Elsa Wiguna 6-0, 7-6 (0) at the National Tennis Centre of the Hassanal Bolkiah National Sports Complex in Berakas.
Second seed Tio Juliandi Hutauruk of Indonesia came from behind to beat Japan's 16th seed Rio Noguchi 3-6, 6-2, 6-3 while Singaporean third seed Joshua Liu was thrashed 6-1, 6-1 by Thailand's Pattanapong Borisutpong.
Over in the girl's singles, Japanese top seed Miyo Kobayashi moved into the last four after a 6-1, 6-3 win over Indonesian seventh seed Faiza Munabari Saskia.
Kobayashi will meet fellow Japanese Saya Usui after the sixth seed breezed into the semi-finals with a comfortable 6-0, 6-0 win over Philippines' Maia Bernadette Balce, who was ranked third.