DUBAI, United Arab Emirates -- American teen Coco Gauff led a day of upsets in the second round of the Dubai Championships when top-seeded Elina Svitolina lost and Petra Kvitova dropped out with a hip problem.
The 16-year-old Gauff fought back to defeat 12th-seeded Marketa Vondrousova 3-6, 6-0, 6-4 to set up a third-round clash with Tereza Martincova, who upset the fifth-seeded Kiki Bertens 6-1, 6-4.
Svetlana Kuznetsova upset two-time champion Svitolina 2-6, 6-4, 6-1, completing her comeback win in just under two hours and will face Barbora Krejcikova in the third round. The Czech defeated Jelena Ostapenko 6-3, 6-1.
Another teenager, 19-year-old Anastasia Potapova, defeated 11th-seeded Madison Keys 6-4, 6-3.
Kvitova, who defeated Garbine Muguruza to win the Qatar Open, retired with Jil Teichmann leading 6-2, 3-4. Kvitova said she’s had an adductor problem since the semifinal in Doha.
French Open champion Iga Swiatek eased past lucky loser Misaki Doi, 6-2, 6-4 for a third-round clash with Muguruza, who defeated American teenager Amanda Anisimova, 6-4, 6-2.
The second-seeded Karolina Pliskova had to dig hard for a 6-3, 6-7 (5), 6-2 win over Anastasija Sevastova and the sixth-seeded Belinda Bencic also had a tough match in beating Veronika Kudermetova 6-4, 5-7, 6-4. Bencic needed five match points to seal her win.
Elise Mertens defeated Shelby Rogers 6-3, 6-3, but another American, Jessica Pegula, prevailed with a 6-1, 6-2 win over Kristina Mladenovic.
There were wins, too, for Caroline Garcia, Anett Kontaveit, Aryna Sabalenka, and Ons Jabeur.