Qualifier Katerina Siniakova upset second seed Sara Errani in the quarter-finals of the Ericsson Open in Bastad, Sweden.
The 20-year-old Czech, who has never won a single title on tour, defeated her Italian opponent 7-6(7/2) 6-3.
She will face home favourite Johanna Larsson, who was a 7-5 6-1 winner over fourth seed Annika Beck, in the last four.
The other semi-final pits German duo Julia Goerges and Laura Siegemund against each other.
Goerges came from a set down to see off Karin Knapp 4-6 6-2 6-3, with Siegemund beating Lara Arruabarrena 7-5 6-3.
Source: PA
