Kirsten Flipkens crashed out of the Istanbul Cup with a straight-sets second-round defeat to world number 129 Kateryna Kozlova.
Ukraine's Kozlova dumped fourth seed Flipkens out 6-3 6-4 to set up a quarter-final meeting with Latvian Anastasija Sevastova.
World number 96 Sevastova derailed eighth seed Johanna Larsson's tilt, dispatching the seed 6-4 6-3.
Qualifier Kristina Kucova beat seventh seed Kateryna Bondarenko in a three-set thriller 6-3 1-6 7-5, the world number 139 booking a quarter-final with Stefanie Voegele, who beat Andreea Mitu 6-4 6-1.
Sixth seed Nao Hibino needed three sets to see off qualifier Reka-Luca Jani from Hungary 2-6 6-2 6-3.
Turkey's Cagla Buyukakcay had few problems seeing off qualifier Sorana Cirstea 6-4 6-2 to set up a last-eight battle with Hibino.
Source: PA
