Veronika Kudermetova upset the Doha Open seedings to defeat American teenager Coco Gauff 6-2, 3-6, 6-1 on Thursday and set up a semifinal clash with world No 1 Iga Swiatek.
Russian 25-year-old Kudermetova, ranked eight, needed just over two hours to complete victory over the world No 4.
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If she is to reach a first WTA final since Istanbul last April, Kudermetova will have to get past a refreshed Swiatek.
The reigning French and US Open champion reached the last-four when last weekend’s Abu Dhabi title winner Belinda Bencic withdrew from their quarterfinal.