Paris - Ashleigh Barty and Marketa Vondrousova set-up a Roland Garros final showdown on Friday, shrugging off a sexism row which had seen their semi-finals shifted away from the tournament's showpiece court.
Barty reached her first final at the majors, coming back from a set and 0-3 down to defeat 17-year-old Amanda Anisimova 6-7 (4/7), 6-3, 6-3 in a rollercoaster semi-final.
Czech teenager Marketa Vondrousova also made sure of her place in a maiden final at the Slams by edging out Britain's Johanna Konta 7-5, 7-6 (7/2).
Vondrousova is the first teenager in a Paris final since Ana Ivanovic in 2007.
Eighth seed Barty, 23, is the first Australian in a French Open final since Samantha Stosur finished runner-up in 2010.
"That was amazing, both good and bad," said Barty who will rise to the top three in the rankings next week.
"It was the hardest thing that I ever had to do.
"I am really proud of the way I fought especially in the conditions which were cold and windy.
"Now I can't wait for the final, it's incredible."
Both semi-finals got underway after accusations of sexism were made against French Open organisers who had decided to shift the matches away from the showpiece Court Philippe Chatrier.
The main arena had already been scheduled to stage the men's semi-finals between Rafael Nadal and Roger Federer and Novak Djokovic against Dominic Thiem.
The WTA said the decision, taken after Wednesday's play was washed out and prompted by fears of more rain Friday, was "unfair and inappropriate".
Former world number one Amelie Mauresmo of France said it was a "disgrace".
Barty, 23, raced into a 4-0 lead with successive breaks as Anisimova, plagued with nerves, managed just one point.
The 17-year-old saved two set points in the sixth game to finally get on the board and retrieved a break for 2-5.
She broke twice again for 6-5 but faltered when she served for the set before securing the tiebreak.
Anisimova then led 3-0 in the second set, with Barty failing to win a point.
However, in a perfect capsule of the unpredictable semi-final, played out in front of a half-full Court Suzanne Lenglen, Barty claimed the next six games to level the tie.
The Australian, who once famously took a break from tennis to pursue a cricket career, even recovered from a break at 1-2 down in the decider.
She eventually held her nerve as Anisimova, bidding to become the youngest finalist in Paris since Martina Hingis in 1997, fell apart despite gamely saving five match points.
Over on a damp and windy Court Simonne Mathieu, world number 38 Vondrousova battled past 26th seed Konta who was bidding to become Britain's first female French Open finalist since Sue Barker won the 1976 title.
Konta looked the stronger player for large periods of the match but a staggering 41 unforced errors proved costly.
The match was played in an atmosphere more associated with first-round ties rather than semi-finals - in front of a smattering of spectators on the 5 000-capacity arena.
Konta made a quick start as Vondrousova struggled with the wind and her nerves on serve - the Briton forging 5-3 ahead.
But the 28-year-old stuttered with a one-set lead in sight, missing three set points and then being broken when serving for the opener.
Vondrousova took full advantage, reeling off four straight games to make Konta pay.
Konta gathered herself, though, and took total control of the second set with an early break, moving 5-3 in front again.
But she tightened up once more when the pressure was on, dropping serve when one game from forcing a decider in a downpour of errors.
With light rain falling on Roland Garros, Vondrousova sealed victory by racing through the tie-break and into the final.