PARIS (AFP) - Kiki Bertens became the first Dutchwoman in 45 years to reach the French Open semi-finals on Thursday with a 7-5, 6-2 win over Swiss eighth seed Timea Bacsinszky.

Bertens, the world number 58, will be playing in her maiden Grand Slam semi-final where she will on Friday face world number one Serena Williams.

Victory for Bertens was her 12th successive victory having arrived in Paris from Nuremburg where she had won the title as a qualifier.

In an error-hit quarter-final, which featured 11 breaks of serve and played on a half-empty Suzanne Lenglen court, the 24-year-old Bertens is the first Dutchwoman to get to the last four since Marijke Schaar in 1971.

She had knocked out Australian Open champion and third seed Angelique Kerber in the first round before seeing off Bacsinszky, a semi-finalist in Paris last year.

"It's unbelievable," said Bertens who started the Nuremburg event at 89 in the world but will now break the top 30 after her run in Paris.

"To be in the semis, it's just crazy. To play Serena it will be a great match. She's the number one in the world.

"I will just go out there and try and have fun and give it my all."

There were seven breaks of serve in the opening set which ended with Bertens in control of the tie but needing to have her left calf strapped.

She raced into a 4-0 lead in the second set before Bacsinszky, who was to end the match with 40 unforced errors, briefly rallied.

But it was all too little, too late and Bertens' powerful, deep hitting gave her victory on a second match point.