Sam Stosur has battled past Chinese Taipei's Kai-Chen Chang to set up a meeting with either Yuxuan Zhang or Jie Zheng.
The Australian had her work cut out in the opening set, as the 86th-ranked professional matched her game for game on Rod Laver.
However, the home favourite powered to a 7-3 victory on the tie breaker after nearly an hour of punishing play.
The 21-year-old - competing in her first Grand Slam tournament - was not fading into the background in front of the Australian public.
She hit a number of searing winners, while Stosur looked nervous.
The 2011 US Open champion used all of her experience in procuring the crucial break in the second set on her way to a 7-6[3] 6-3 victory.
