MELBOURNE, Australia (AP) — Second-seeded Karolina Pliskova and No. 6 Belinda Bencic went the same way as Serena Williams and defending champion Naomi Osaka by exiting the Australian Open in a chaotic third round.

Pliskova, a semifinalist here last year, lost 7-6 (4), 7-6 (3) to 30th-seeded Anastasia Pavlyuchenkova in match lasting almost 2 1/2 hours on Saturday. It was an ominous start, with Pliskova needing almost 18 minutes and fending off six break-point chances before holding in her first service game.

Seven-time Australian Open champion Williams and Osaka lost at the same stage the previous day, when 2018 champion Caroline Wozniacki went into retirement after a loss. Williams, still in pursuit of Margaret Court's all-time record 24 majors after failing to add to her career tally since the 2017 Australian Open, lost to Wang Qiang, a player she'd beaten in 44 minutes at last year's U.S. Open. Osaka, who won back-to-back majors at the 2018 U.S. Open and last year here in Australia, lost to 15-year-old Coco Gauff.

Three-time major winner Angelique Kerber bucked the trend by beating Camila Giorgi 6-2, 6-7 (4), 6-3 in Saturday's opening match on Margaret Court Arena.

The 2016 Australian Open winner will play Pavlyuchenkova for a spot in the quarterfinals.

"It was a tough battle," the 17th-seeded Kerber said. “It's great to be in the second week in Melbourne again. It's still a long way.”

Pavlyuchenkova had taken only one set off Pliskova in six previous matches, but changed her approach this time and attacked one of the best serves in women's tennis.

“I even had goosebumps after some points,” the 28-year-old Russian said. “And to beat Karolina for the first time, it’s amazing.”

Pavlyuchenkova won the junior title at Melbourne Park more than a decade ago and said she was using that as motivation this time.

“It brings me like “you can do it,'" confidence, she said, ”Keep going.”

Bencic, a semifinalist at the U.S. Open last September, was rolled 6-0, 6-1 in 49 minutes by 28th-seeded Anett Kontaveit, who will next play Iga Swiatek, the No. 59-ranked player from Poland who took out 19th-seeded Donna Vekic 7-5, 6-3.

Former No. 1-ranked Simona Halep was playing Yulia Putinseva in the second match on Rod Laver Arena, and men's No. 1 Rafael Nadal was playing No. 27 Pablo Carreno Busta in the afternoon match on the main court at Melbourne Park.

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