Elsewhere, Poland’s Kamil Majchrzak eliminated Russian ninth seed Karen Khachanov in an epic second round.
Majchrzak came back from two sets, overturned the fifth inning deficit of 5-2 and saved 5 match points to 2-6 6-7 (4-7) 6-4 7-5 7-5 7-6 (10-5).
Meanwhile, Andrey Rublev had a tough four-set encounter with American Tristan Boyer.
Boyer ranked 113th in the world, taking the third set before the 15th seed Rublev won 6-3 6-3 5-7 7-6 (7-4).
Rublev’s next opponent will be Coleman Wong, who supported his historically-created first-round victory by defeating Australia’s Adam Walton in four innings.
Huang’s first round success made him the first male player in Hong Kong to win a Grand Slam singles match in the open era.
Lorenzo Musetti is the 6-4 6-0 6-2 champion of Belgian veteran David Goffin, and the tenth seed will face Italy’s Flavio Cobolli.
No. 24 seed Cobolli won the race in the second round of a marathon, beating U.S. Jenson Brooksby for four and a half hours.
