Gauff gets mad, then gets farther in Dubai

Coco Gauff rallied from a slow start and a secondset argument with the chair umpire to beat Karolina Pliskova 2-6, 6-4, 6-3 and reach the quarterfinals of the Dubai (UAE) Championships. The third-seeded Gauff ended Pliskova's 11-match winning streak.

The 19-year-old American built a 4-2 lead in the second set before a lengthy back-and-forth with chair umpire Pierre Bacchi. Gauff complained to Bacchi that he called her serve at deuce out only after Pliskova returned it into the net.

Gauff had to repeat her first serve and went on to hold for a 5-2 lead. The U.S. Open champion said the argument “fueled” her.

Gauff will next face Anna Kalinskaya after the Russian beat ninth-seeded Jelena Ostapenko 6-4, 7-5.

Top-ranked Iga Swiatek moved to the last eight, beating two-time Dubai champ Elina Svitolina 6-1, 6-4.

Fourth-seeded Elena Rybakina had a tougher time reaching the quarterfinals. She outlasted Magdalena Frech 7-6 (5), 3-6, 6-4.

Swiatek will next play sixth-seeded Qinwen Zheng, who eliminated Anastasia Potapova 6-3, 6-2. Rybakina has a quarterfinal match against Jasmine Paolini. The Italian defeated eighth-seeded Maria Sakkari 6-4, 6-2.

The other quarterfinal match is seventh-seeded Marketa Vondrousova against Sorana Cirstea.

• João Fonseca became the first player born in 2006 to win an ATP tour-level match when the 17-yearold Brazilian beat seventhseeded Arthur Fils 6-0, 6-4 at the Rio Open.

Fonseca defeated the No. 36-ranked Frenchman in front of raucous fans at the clay court event in Rio de Janeiro. He knelt on the court in tears to celebrate.