The 17-year-old's dream run at the Australian Open continued with a straight sets win over Australia's Rinky Hijikata in the quarter-finals.
McHugh defeated the home favourite 6-4 6-2 and now faces Chun Hsin Tseng of Taipei - whom he beat in last week's warm-up event in Traralgon.
The first break of serve in the match went early to McHugh in the third game of the first set, but Hijikata back in the eighth game to square things at 4-4.
However immediately broke back and then served out to take the opening set 6-4.
In the second set McHugh broke to go 3-2 up then consolidated with another break before serving out to take his place in the last four.
Unseeded McHugh now faces number six seed Tseng, while the other semi will see Serbia's number two seed Marko Miladinovic - also beaten by McHugh in Traralgon - up against America's Sebastian Korda, son of 1998 Australian Open senior champion Petr Korda.