Swiss Olympic champion Belinda Bencic reached the last eight of the WTA grass-court tournament in Berlin on Thursday with a 6-4, 1-6, 6-1 win over Russia’s Anna Kalinskaya. The 25-year-old Bencic will meet another Russian in the quarter-finals as she awaits the later winner of Ludmilla Samsonova v Weronika Kudermetova. Top seed Ons Jabeur of Tunisia also reached the last eight on Friday with a 6-2, 7-6 (10-8) win over American Alycia Parks.