Hsieh, ranked 23rd in the world juniors, endured the sweltering heat at the Rizal Memorial Tennis Center and refused to be cowed by the cheers of the home crowd to complete the victory in under one hour and set a meeting with eighth seed Pichaya Laosirichon of Thailand, a 4-6, 6-2, 6-3 winner over Australian Sevvy Gallos.
Also moving into the quarterfinals were girls’ division top seed Angelique Widjaja of Indonesia and the boys’ section top two seeds — Americans Jonathan Chu and Prakash Amritraj.
Widjaja ousted Thailand’s Montinee Tangphong, 6-2, 6-1, to arrange a date with Australian Adriana Szili, who dumped Indian Megha Vakaria, 6-1, 6-3.
Chu, the world No. 46, came back from a first set loss to oust Jan Stancik of Slovakia, 5-7, 6-4, 6-3, while Amritraj, son of the great Vijay Amritraj with a No. 62 ranking, kept pace by booting out Indian Nishank Mishra, 6-1, 6-2.
Completing the boys’ division quarterfinals cast were lucky loser Pawel Dilaj of Poland, Clinton Letcher of Australia, qualifier Scott Oudsema of the USA, Luka Gregore of Slovenia, Yu Hiu Tung of Hong Kong and Michael Przsicny of Poland.
Dilaj, who made it to the main draw when one of the direct entries failed to arrive, retained his luck with a 6-4, 6-3, win over Eko Kuriawan of Indonesia while Letcher dropped the axe on fourth seed Kumar Sipaeya of India, 7-5, 6-4, and Oudsema saw Thailand’s Tara Tanthasuwanalert retire after losing the first set, 4-6, and trailing 0-1 in the second.
Gregore became the second giant killer for the day when he ousted fifth seed Jason Zommerman of the USA, 6-2, 7-6 (5), while Yu won over Thailand’s Anuwat Dalodom, 3-6, 6-0, 6-3, and Przsieny arranged a date with Amritraj by beating Vinod Kumar Seva of India, 6-2, 6-2.
Also making the last eight in the distaff side were third seed Sanja Mirza of India, No. 4 Amber Liu of the USA, Jung Yoo-mi of South Korea and Alexandra McGoodwin of the USA.