Russian 31st seed Anastasia Pavlyuchenkova continued her late bloom by reaching a first Grand Slam final with victory over Slovenia's Tamara Zidansek in the French Open last four.
Against another debutant at this stage, she won 7-5 6-3 on the Paris clay.
Pavlyuchenkova will face Greek 17th seed Maria Sakkari or Czech Barbora Krejcikova, who play later on Thursday.
Those two players are also competing in a Grand Slam semi-final for the first time.
It is the first time since 1978 - and only the second time in the Open era - that a Grand Slam women's singles tournament has had four semi-final debutants.