Two-time major winner Garbine Muguruza withdrew from her quarterfinal match on Thursday at the Hobart International in Australia because of an illness.
Second-seeded Spaniard was slated to play Russia's Veronika Kudermetova, who now advances to the semifinals.
British qualifier Heather Watson recorded a 6-7 (5), 6-4, 7-5 rain-delayed victory over top-seeded Elise Mertens of Belgium in a match that lasted three hours and 33 minutes. She will face No. 3 Elena Rybakina of Kazakhstan, who posted a 6-7 (4), 7-6 (2), 7-5 victory over Aussie wild card Lizette Cabrera.
No. 4 Shuai Zhang of China breezed to a 6-1, 6-4 win over Lauren Davis in the other quarterfinal match.
Top-seeded Ashleigh Barty continued her success in her home country with a 6-3, 6-3 win over No. 8 Marketa Vondrousova of the Czech Republic in their quarterfinal match in Australia.
While Barty had a relatively easy time of it in her French Open final rematch with Vondrousova, No. 2 seed Simona Halep of Romania fell in straight sets to No. 6 Aryna Sabalenka of Belarus. Sabalenka recorded a 6-4, 6-2 win over Halep.
Danielle Collins will face Barty in the semifinals after posting a 6-3, 6-1 win over fourth-seeded Swiss Belinda Bencic, while Ukrainian teenager Dayana Yastremska enjoyed a 6-4, 6-3 victory over Croatia's Donna Vekic.
--Field Level Media