Kristina Mladenovic recovered from a set and a break down to halt Maria Sharapova's comeback on the WTA Tour in the Stuttgart Open semi-finals.

After a 15-month doping ban, the Russian's participation as a wildcard at this Premier event — one she has won three times — was the subject of much controversy but the five-time grand-slam champion had quelled some of her critics in not dropping a set en route to Sunday's (AEST) last-four meeting.

That trend continued as she took the first set with ease against her unseeded opponent and when Sharapova broke right at the start of the second, a comfortable victory and a place in the final seemed an inevitability.

Mladenovic remained unbowed, however, and fought back admirably to level before both women appeared beset by nerves towards the end of the decider.

The Frenchwoman was broken when serving for the match at 5-3, but hit back immediately to end Sharapova's return and leave the Russian relying on another wildcard if she is to compete at the French Open next month.

Mladenovic's triumphant finish was a far cry from her opening to the match, a double fault handing Sharapova a lead that she would not relinquish.

It looked as though the match could be over swiftly as Sharapova carried that momentum into the second with an instant break, but a stunning backhand up the line saw Mladenovic level at 2-2, a hold to love in the next a sign of her growing confidence.

The Russian wasted four break opportunities to wrest control back in her favour, and was duly punished in game 12 as a double fault and an errant forehand saw Mladenovic take the set.

Another wayward forehand gave Mladenovic a 4-2 advantage in the decider, but that was swiftly cancelled out as Sharapova threatened to turn things back in her favour.

It was not to be, though, as a delicate half-volley set up match point for Mladenovic, who put away a backhand slice down the line to secure her place in Monday's (AEST) final and end Sharapova's controversial comeback.