Petra Kvitova, chasing a fourth title on the Caja Magica clay, has now won her last five matches over Kristina Mladenovic in straight sets.
Former Roland Garros doubles champions Caroline Garcia and Kristina Mladenovic beat Simona Halep and Monica Niculescu to secure a final date against Australia.
Defending champion Andy Murray added his voice to the growing list of unhappy players.
After winning three rounds since her return to tennis after serving a doping ban, Maria Sharapova fell in three sets to Kristina Mladenovic in the semifinals.
With the Fed Cup tie level at 2-2, US Open finalist Karolina Pliskova teamed up with Barbora Strycova to defeat French Open doubles champions Caroline Garcia and Kristina Mladenovic 7-5, 7-5 to prolong the Czech Republic's reign
Bethanie Mattek-Sands and Lucie Safarova defeated top seeds Caroline Garcia and Kristina Mladenovic in three sets to win the 2016 US Open women's doubles title
Seventh seeds Sania Mirza and Barbora Strycova defeated American-Japanese pair of Nicole Gibbs and Nao Hibino 6-4, 7-5 to enter the quarter-finals of US Open.
If the temporary ban is upheld Caroline Garcia, the French number one, and Kristina Mladenovic, the number two, will miss the final of the Fed Cup against the Czech Republic in November
Caroline Garcia and Kristina Mladenovic became the first French duo to win the French Open after 46 years as they defeated Ekaterina Makarova and Elena Vesnina to clinch the women's doubles title.
Despite playing well in patches, the top seeded Indo-Swiss pair of Sania Mirza and Martina Hingis struggled to find their rhythm as their French opponents claimed a 6-4, 6-4 win.
The 22-year-old Switzerland-based player of Serbian parentage won an eventful match by 2-6, 6-0, 7-6 (7/4), upsetting a seed for the third successive time and announcing herself only ten days before Wimbledon as a force to be reckoned with on grass courts.