Johanna Konta celebrated her birthday with a three-set win over Czech teenager Marketa Vondrousova to reach the Italian Open semi-finals on Friday.

The Briton, who defeated Americans Sloane Stephens and Venus Williams in her two matches on Thursday, will face sixth-seeded Kiki Bertens on Saturday for a place in the final.

Madrid Open champion Bertens reached the last four after Japan’s world No.1 Naomi Osaka pulled out with a thumb injury ahead of their quarter-final.

Osaka said she was unable to grip her racket properly after winning both her matches in straight-sets on Thursday.

Wednesday’s rain forced the players to play two matches in a day and Osaka beat both Slovakia’s Dominika Cibulkova and Romania’s Mihaela Buzarnescu in straight sets.

“I woke up (on Friday) morning and couldn’t really move my thumb,” Osaka told a press conference.

“I tried to practice and grip my racket, but I couldn’t and then I kept feeling this pain whenever I tried to move my hand in different directions.

“Right now, I’m really, not mad, but in between sad and disappointed because I really wanted to play my match.”

Konta, celebrating her 28th birthday, hit 42 winners against the 19-year-old Vondrousova and dominated the final set to clinch victory in one hour 53 minutes.

She heads towards this month’s French Open in fine form on clay, having finished runner-up in the Morocco Open at the start of May.

Fourth seed Karolina Pliskova recorded her 500th career win with a 6-7 (5-7) 6-2 6-2 victory over Victoria Azarenka.

Czech fourth seed, Pliskova, who accounted for Australia’s Ajla Tomljanovic in round two, will now face Maria Sakkari of Greece, who put out France’s Kristina Mladenovic 4-6 6-3 6-0, in the other semi-final late on Friday.