Coming into the tournament ranked 20th in the world, Suzi-Rose Deegan, Sara-Rose Smith, Alexandra Fowler and Ruby Porter faced the number two ranked team in Ukraine.
Fowler and Deegan combined for first four points of the game, utilising their size to seal positions down low.
That edge in the paint allowed Australia to continually reel in the offensive rebounds which gave them several second chance points.
The extra possessions also kept the ball out of Ukraine's hands as they struggled to trim the deficit with Australia taking charge.
The Aussies moved in front 10-3 midway through the game as Porter drilled a couple of nice runners before Smith connected on another drive to open up a game-high 11-point advantage.
Ukraine were able to hit a couple of late free-throws but Australia finished with a 16-6 victory as they advanced to the Semi-Finals to take on France.
The Semi-Finals and medal games will both be held early tomorrow morning Australian time and you can watch a 24/7 stream of the Youth Olympic Games here courtesy of the Australian Olympic Committee.
That link also offers a replay of Australia's games via the VOD (video on demand) button within the player while you can keep up to date with stats here.
The Australian 3x3 Women's Schedule for the 2018 Buenos Aires Youth Olympic Games (all times AEDT):
October 11: Australia def. Netherlands 11-7
October 11: Australia def. Czech Republic 15-11
October 15: Australia def. by Spain 7-12
October 15: Australia def. Estonia 19-15
October 17: Quarter-Finals- Australia def. Ukraine 16-6
October 18: Semi-Final- Australia vs. France at 1am
October 18: Bronze medal game at 2.40am or gold medal game at 3.30am