Tunisia's Ons Jabeur advanced to the quarterfinals of the Qatar Total Open with a 6-4, 3-6, 6-3 upset of former World No. 1 and 2017 champion Karolina Pliskova on Wednesday in Doha.
Jabeur, who reached her first Grand Slam quarterfinal earlier this year at the Australian Open, defeated the third-seeded Czech star in one hour, 47 minutes. She finished with 33 winners to just 18 unforced errors and broke Pliskova in the sixth and eighth games of the deciding set.
Jabeur's opponent in the final eight is another tough opponent from the Czech Republic, No. 8 seed Petra Kvitova. Kvitova also survived a three-setter Wednesday, posting a 6-2, 5-7, 6-1 victory in windy conditions against Jelena Ostapenko of Latvia.
"There's no chance to have tactics in this wind," Kvitova said. "The wind changes everything. It's difficult to put the serve in and she returned the second serve well. It was difficult from the first point."
No. 4 seed Belinda Bencic of Switzerland booked her place in the quarterfinals with a 6-4, 6-3 win over Kazakhstan's Yulia Putintseva. She will face Russian Svetlana Kuznetsova, who advanced in a walkover due to American Amanda Anisimova's withdrawal because of an illness.
No. 11 seed Garbine Muguruza eliminated Ukrainian teenager Dayana Yastremska 6-2, 6-4 to set up a meeting with top-seeded Ashleigh Barty of Australia. Barty also had a walkover in her third round match, as Kazakhstan's Elena Rybakina withdrew Tuesday with an abductor strain.
"She hits a lot of strong shots, some of them go in, some of them go out sometimes," said Muguruza, who took advantage of eight double faults by the 19-year-old Yastremska. "So I felt that I was very solid with my game and it was working since the beginning."
The final quarterfinal pits No. 9 seed Aryna Sabalenka of Belarus against China's Saisai Zheng. Zheng rallied for a 3-6, 6-3, 6-4 upset of seventh-seeded Kiki Bertens of the Netherlands, while Sabalenka took out No. 15 Maria Sakkari of Greece in straight sets, 6-3, 6-0.
Unseeded Canadian Leylah Annie Fernandez, the reigning French Open girls singles champion, knocked off eighth-seeded Nao Hibino of Japan 6-3, 6-0 to reach the quarterfinals in Acapulco, Mexico.
The 17-year-old Fernandez, the 190th-ranked player in the world, needed only 64 minutes to oust the world's 71st-ranked player in their career fourth match. Fernandez is in a WTA main draw for the fifth time in her career. She advances to face Russia's Anastasia Potapova, an 18-year-old who defeated Germany's Tatjana Maria 6-3, 6-3.
In other Round of 16 matches, Christina McHale rallied to top Caroline Dolehide 5-7, 6-4, 6-3 in an All-American battle, and fellow American Katie Volynets fell to Mexico's Renata Zarazua 4-6, 7-5, 6-0. Zarazua, ranked 270th in the world, stunned top-seeded Sloane Stephens of the United States 6-4, 6-2 in the first round.
In a quarterfinal match Thursday, McHale will meet seventh-seeded Heather Watson of Great Britain, who stopped Ukraine's Kateryna Bondarenko 7-6 (2), 6-2.
Also advancing to the quarterfinals were sixth-seeded Lin Zhu of China and Slovenia's Tamara Zidansek, both in straight sets, and China's Xiyu Wang, who needed three sets to defeat Italy's Sara Errani.
--Field Level Media