• Spain's Carla Suarez Navarro stretches out for a return shot to Anett Kontaveit of Estonia during their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 21, 2018. (AP Photo/Dita Alangkara) Photo: Dita Alangkara / Copyright 2018 The Associated Press. All rights reserved.
Photo: Dita Alangkara
Image 1of/1

Caption

Close

Image 1 of 1
Spain's Carla Suarez Navarro stretches out for a return shot to Anett Kontaveit of Estonia during their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 21, 2018. (AP Photo/Dita Alangkara) less
Spain's Carla Suarez Navarro stretches out for a return shot to Anett Kontaveit of Estonia during their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 21, ... more
Photo: Dita Alangkara

Melbourne, Australia

Carla Suarez Navarro is the first player through to the Australian Open quarterfinals after beating Anett Kontaveit 4-6, 6-4, 8-6 in the opening fourth-round match at Rod Laver Arena on Saturday.

Kontaveit, who has lost in the first round at Melbourne Park the past two years, served for the match at 5-4, but had her service broken by the Spanish player.

Suarez Navarro advanced on her third match point when the 22-year-old Estonian player hit a forehand long.

Suarez Navarro will play second-seeded Caroline Wozniacki, who swept past Magdalena Rybarikova, 6-3, 6-0 in a later match.

Marin Cilic also advanced to the quarterfinals with a 6-7, 6-3, 7-6, 7-6 victory over Pablo Carreno Busta.

Fourth-seeded Alexander Zverev made yet another puzzling early exit at a Grand Slam, dropping 12 of the final 15 games in a 5-7, 7-6 (3), 2-6, 6-3, 6-0 loss to fellow rising star Hyeon Chung in the third round.

More troubling, Zverev has notched multiple wins over top-10 players like Roger Federer, Novak Djokovic and Stan Wawrinka at regular ATP tournaments, but has never managed to beat a player ranked in the top 50 at a major.

When asked after his match whether his problem in best-of-five-set matches was physical or mental, a downcast Zverev replied, "Definitely not physical."

"I have some figuring out to do, what happens to me in deciding moments in Grand Slam," he said. "It happened at Wimbledon. It happened in New York. It happened here."

Angelique Kerber routed Maria Sharapova 6-1, 6-3 in one hour and four minutes.

Federer and Novak Djokovic were almost as ruthless in their straight-sets third-round wins. Federer swept No. 29 Richard Gasquet, and Djokovic routed No. 21 Albert Ramos-Vinolas.

Whereas, women's No. 1 Simona Halep took a longer route — equaling a mark in Melbourne for endurance.

Halep's 4-6, 6-4, 15-13 win over American Lauren Davis took three hours, 45 minutes. The third set alone took two hours, 22 minutes.

Madison Keys is the only American woman to reach the fourth round.

Sixth-seeded Karolina Pliskova beat No. 29 Lucie Safarova 7-6 (6), 7-5.

Hsieh Su-wei followed up her win over Wimbledon champion Garbine Muguruza by beating No. 26 Agnieszka Radwanska 6-2, 7-5 to return to the fourth round at Melbourne Park for the first time in a decade.

Juan Martin del Potro lost to Tomas Berdych.