Dy, who moved up to No. 59 in the world junior rankings, breezed through the first set before encountering problems in the second set where Chang managed to send it into a tiebreak.
But Dy, who is coming off a semifinal finish and two quarterfinal efforts in tournaments in Indonesia, Malaysia and Thailand before this event, overcame Chang with solid baseline play to barge into the round-of-16.
There, she’ll play regional rival ninth pick Varatchay Wongteancha of Thailand, a 5-7, 6-1, 6-1 winner over Guo Xuan-Yu of China.
"She played really well, her confidence is really up," said tennis vice president for international affairs Ajay Pathak referring to the double bronze medalist in December’s 23rd Southeast Asian Games.
Kyle Dandan, in contrast, fell victim to a big serving Greg Jones in a heartbreaking 0-6, 6-4, 6-7 (7) defeat that lasted almost three hours.
Dandan, 16, had his chances though, going up 7-6 in the third set tiebreak for a chance to seal the win but he dropped the next three points, no thanks to a pair of unforced errors and Jones’ power serves.
"I had a slow start again but I came back. I just couldn’t deliver when needed," said Dandan.
Another local bet Noelle Zoleta, 17, was also shown the door, losing to top seed Sacha Jones of New Zealand, 2-6, 6-7 (1) that made Dy the sole local bet in the prestigious event.
Along the way, Dy could face Jones, who defeated the 16-year-old Fil-Am twice going into this event, the first two weeks ago, 2-6, 3-6, in Malaysia and the other last week, 5-7, 1-6, in Thailand where the new Zealander won.
"But Denise said she’ll get back at her (Jones) if she’ll have the opportunity," said Pathak.
Like Jones in the girls’ division, boys’ top seed Sanam Singh of India also made it to the next round with a tough 6-2, 6-7 (6), 6-0 win over Agung Dewantoro of Indonesia.
Fourteenth seed Dennis Lajola, a Hawaii-based American who has Filipino blood, withdrew.