Former champion Andrea Petkovic of Germany lost 6-4, 6-4 to Monica Puig of Puerto Rico in the quarterfinals of the Strasbourg International on Thursday.
The fourth-seeded Petkovic, who won the tournament in 2011, missed chances to break in the first set and Puig capitalized to reach her first semifinal.
The German was the only seed left in the tournament, which will see a new champion.
Julia Goerges of Germany was beaten by Madison Keys of the United States 6-2, 2-6, 6-2. Keys will meet Puig in the semifinals.
Another American was through, as Christina McHale was 6-2, 3-1 up against Zarina Diyas, before the Kazakh retired through injury.
McHale faces Silvia Soler-Espinosa of Spain, who edged Camila Giorgi of Italy 3-6, 6-4, 7-5.