One fourth-seeded player advanced, another did not.
Naomi Osaka of Japan rallied past No. 13 Anastasija Sevastova of Latvia 4-6, 6-3, 6-4 on Monday at Rod Laver Arena to reach the women’s quarterfinals of the Australian Open.
In the men’s draw, however, Alexander Zverev of Germany fell to 16th-seeded Milos Raonic of Canada 6-1, 6-1, 7-6 (5), also in a fourth-round match on the same court.
Also reaching the end of the road at Melbourne Park was American Madison Keys, who was defeated by sixth-seeded Elina Svitolina of Ukraine 6-2, 1-6, 6-1.
The marquee matches of the session were played at night, with top-seeded Simona Halep of Romania facing 16th-seeded Serena Williams of the United States, and top-seeded Novak Djokovic of Serbia going against No. 15 Daniil Medvedev of Russia.
Serving to tie the match, Osaka fended off a break-back point with a forehand volley after a long, tense baseline rally. Two points later, the match was heading into the deciding set.
Osaka broke serve to open the third set to maintain the momentum.
Zverev also did some breaking, but it was his racket that got destroyed by the player during the second set. After sitting on his sideline chair, Zverev smashed the racket against the ground eight times and tossed it aside.
“I played incredible today, I did a lot of things incredibly well today and I’m very proud of that,” Raonic said.
Svitolina fended off five break points in the third game of the third set that went to deuce 11 times and lasted more than 15 minutes. She broke Keys’ serve at the first opportunity in the next game and finished off the match quickly.
“I think that in the third set we obviously had a really long game ... and that was where all the momentum swung,” Keys said. “For me to get broken easily right after, I think I lost all the momentum that I had in the second set.”
Late Sunday, Roger Federer’s bid for a third consecutive Open men’s title ended in a 6-7 (11), 7-6 (3), 7-5, 7-6 (5) loss to 20-year-old Stefanos Tsitsipas, the first player from Greece to reach a Grand Slam event quarterfinal.
The third-seeded Federer failed to convert any of the 12 break points he earned. Tsitsipas was one for three, his only break coming in the last game of the third set.
“It was a dream come true for me just facing him,” Tsitsipas said. “Winning at the end? I cannot describe it, you know.”
At 37, the Swiss was the oldest man left in the tournament. Tsitsipas is the youngest.
In women’s play, fifth-seeded Sloane Stephens of the U.S. lost 6-7 (3), 6-3, 6-3 to Anastasia Pavlyuchenkova of Russia in a fourth-round match that lasted 21/2 hours and finished at nearly 2 a.m. Melbourne time.