The 17-year-old Melbourne-based world No. 154 held his ground against the world No. 43 in the first set but lost his focus in the second before regaining his form to achieve the breakthrough victory in two hours and 20 minutes.
Groth aces seventh seed Martin Sayer of Hong Kong in the Last 4 today. Sayer reached the semifinals via a 3-6, 6-4, 7-5 decision over unseeded Ruben Bemelmans of Belgium.
Sharing the day’s honors were Japanese Shuhei Uzawa in the boys’ singles and Hwan I-Hsuan of Taiwan in the distaff side.
Uzawa emerged as the second of the only two unseeded participants to make the singles semifinals when he bested fellow upsetter Chris Eaton of Great Britain, 7-6 (2), 6-4.
Uzawa plays against sixth seed Abdullah Magdas of Kuwait who stopped 14th seed Lee Hsin-Han of Taiwan, 6-4, 6-1.
Hwang stunned second seed Caroline Wozniacki of Denmark, 7-6 (5), 6-2, to set up a semis duel with third-seed compatriot Hsu Wen-Hsin, who ousted Hong Kong’s Zhang Ling, 6-3, 6-4.
Top seed Chan Yung-Jan rolled past seventh pick Amina Rakhim of Kazakhstan, 6-1, 6-3 and will meet fourth seed Mihaela Buzarnescu of Romania who reached the semis without lifting her racquet after American sixth seed Vania King withdrew with an injured shoulder.