Top seed Petra Martic held her nerve in two tiebreaks to beat Belarusian qualifier Aliaksandra Sasnovich 7-6(5) 7-6(3) to seal a place in the Palermo Ladies Open semi-finals on Friday.

She next faces 24-year-old Estonian fourth seed Anett Kontaveit who hit 57 winners to end Italian teenager Elisabetta Cocciaretto's dream run with a 6-1 4-6 6-1 win.