Defending champion Samantha Stosur has fallen short in her quest to join top-seeded fellow Australian Ashleigh Barty in the semi-finals of the Strasbourg International.

Stosur’s three-year, 13-match winning streak at the French Open lead-up event came to a halt with a 6-4 6-3 quarter-final loss to former Australian Open runner-up Dominica Cibulkova.

Barty earlier on Thursday advanced to her maiden WTA clay-courtsingles semi-final with a 7-5 6-4 victory over the Peter McNamara-coached Qiang Wang.

After crushing Frenchwoman Pauline Parmentier for the loss of just four games in her previous match, Barty had to recover from a service break down in the second set to see off Wang in 88 minutes.

“I knew I had to be ready and it was a great match, a very high level out there,” Barty said after showcasing her full array of shot-making and winning 82 per cent of points on her first serve.

“I had to fight very hard to get back into the second set.

“But I felt very clean off the ground today and probably felt it was my best match this week.”

The world No.17 will play third seed Anastasia Pavlyuchenkova on Friday for a spot in Saturday’s title decider after the Russian beat Kazakh Zarina Diyas 6-4 6-2.

Stosur had beaten Cibulkova in five of their previous six encounters, including all three on clay without dropping a set.

But Australia’s one-time French Open finalist was unable to replicate her imperious form from rounds one and two, dropping twice in each set in falling to Slovakia’s fifth seed in one hour and 33 minutes.

Cibulkova will meet Mihaela Buzarnescu in the semi-finals after the Romanian fourth seed thrashed Su-Wei Hsieh 6-0 6-3.