The Australian, who had only previously reached one slam singles quarter-final, will climb to second in the world rankings following her success.
Dominic Thiem will face Rafael Nadal in the men's final after finishing off a delayed victory over Novak Djokovic in five sets, ending the Serbian's hopes of holding all four slam titles for a second time.
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Outsiders win doubles title
It was no wonder Kevin Krawietz and Andreas Mies dropped to the court in disbelief after winning the men's doubles title. The German pair sit just inside the top 50 in the rankings and have never even played at an ATP Masters tournament. But they are now grand slam champions thanks to a 6-2 7-6 (3) victory over French duo Jeremy Chardy and Fabrice Martin.
Canada looks to have yet another teenage sensation on its hands in Leylah Annie Fernandez. The 16-year-old top seed defeated Emma Navarro of the United States 6-3 6-2 to win the girls' singles title. The country already has three young stars making waves in the senior game in Denis Shapovalov, Felix Auger-Aliassime and Bianca Andreescu.
Who's up next?
After achieving the best win of his career against Djokovic, Thiem must now try to top it by becoming only the third player to beat Nadal at Roland Garros.
The Spaniard is going for his 12th title here and has only ever lost six sets in his previous 11 finals.
It is a rematch of the final 12 months ago, Thiem's first at a grand slam, which Nadal won 6-4 6-3 6-2.