Putintseva had already beaten home favourites Amandine Hesse and Caroline Garcia to reach the last eight of the WTA 125k series hard-court event.
However, she was undone by a third Frenchwoman in the shape of Mladenovic, who triumphed 6-2 7-6 (7-5).
Mladenovic, seeded ninth, dominated the early exchanges and comfortably wrapped up the first set.
The second proved far more even, with Putintseva recovering from an early deficit, but Mladenovic recovered to reach the last four and take her record against Putintseva to 2-1.
She will next face compatriot Oceane Dodin, who continued her dream run by defeating fellow teenager Ana Konjuh 7-5 6-3.
Wildcard Dodin has won all of her matches in straight sets and Mladenovic will have to guard against complacency to reach the final.
On the other side of the draw Francesca Schiavone continued her quest for a seventh WTA Tour singles title by seeing off the challenge of Richel Hogenkamp in a 6-4 7-6 (7-2) win.
Awaiting Schiavone in the semi-final is Tereza Smitkova after she defeated Lesia Tsurenko 6-2 6-3.