Magda Linette defeated third seed Naomi Osaka in three sets at the Citi Open in Washington on Thursday, as seeds Yulia Putintseva and Donna Vekic progressed to the quarter-finals.
Poland's Linette won 6-2 3-6 6-3 in the WTA International event on hard courts to book a meeting with Vekic, the seventh seed having overcome Fanny Stollar 6-2 3-6 7-6 (15-13) following a marathon tie-break in the deciding set.
Putintseva, the eighth seed, ousted home hope Jennifer Brady 7-5 6-2 and will face Svetlana Kuznetsova, the 2014 champion at this event, who brushed aside Ana Bogdan 6-2 6-1.
Zheng Saisai accounted for Ysaline Bonaventure 6-4 6-4 to set up a match against American Allie Kiick, who defeated Britain's Katie Boulter 6-4 5-7 6-1.
