Stuttgart Open: Kostyuk scores big upset against Gauff, fighting back to reach last four

Ukrainian Marta Kostyuk moved into the last four of the Stuttgart Open by edging out American Coco Gauff, the No 3 seed, 3-6, 6-4, 7-6 (6) at the Porsche-Arena.

Kostyuk, ranked No 27, will face No 6 seed Marketa Vondrousova next.

Ahead of her victory, the 21-year-old Ukrainian edged out German wildcard Laura Siegemund (6-3, 6-7 (4), 6-4) and Chinese Qinwen Zheng, the No 5 seed (6-2, 4-6, 7-5).

Gauff, ranked No 3, edged out qualifier Sachia Vickery (6-3, 4-6, 7-5) in the previous round of the Stuttgart tournament.

Stuttgart WTA 500, other quarter-finals results (Porsche-Arena, clay, USD 802.237, most recent results first):

• Iga Swiatek (1) beat Emma Raducanu (WC): 7-6 (2), 6-3
• Marketa Vondrousova beat Aryna Sabalenka (2): 3-6, 6-3, 7-5
• Elena Rybakina (4) beat Jasmine Paolini: 6-3, 5-7, 6-3