Daniil Medvedev, Dayana Yastremska and Linda Noskova have all reached the quarterfinals of the Australian Open, with the latter two making their debut in a Grand Slam singles tournament.

Medvedev defeated Nuno Borges 6-3, 7-6 (4), 5-7, 6-1 on Monday to reach the last eight. He will face either No. 9 Hubert Hurkacz or French wild-card entry Arthur Cazaux.

Yastremska defeated two-time champion Victoria Azarenka 7-6 (6), 6-4, while 18th-ranked Elina Svitolina was trailing Noskova 3-0 when Svitolina retired with a back injury.

Azarenka served for the first set twice and had two set points at 6-5 but couldn't convert, and Yastremska won the opening set on her second chance after 74 minutes. The Ukrainian then led 3-0 in the second set, but Yastremska won six of the next seven games to clinch victory, ending with 37 winners.

"I think I need to take a thousand breaths because my heart, I think, is going to jump out of my body," Yastremska said. "During the match, I was imagining how I lost already like 25 times. I was losing the tiebreak, second set I was losing, I always felt I was running behind the train. But because I'm a little bit of a fighter, I think I won this match and plus the support, it was amazing."

There was no handshake, as is the convention between Ukrainian and Russian and Belarusian players, though Yastremska raised her racket toward Azarenka.

The first game of the Noskova-Svitolina match lasted 11 minutes and contained 20 points. Noskova broke serve and held for 2-0 before Svitolina had a timeout and received treatment on her lower back.

When she resumed, the Ukrainian's serve speed was well down, and her movement appeared compromised. After being broken for a second time and fighting back tears, Svitolina shook Noskova's hand and retired.

Svitolina said the injury happened at the end of the first game.

"I got a spasm, like a shooting pain," she said. "Couldn't do anything, completely locked my back, just very sad. I had some injuries to my back before where it just was tiredness the next day of the match, but this one was really out of nowhere. I felt like someone shot me in the back."

Noskova beat top-ranked Iga Swiatek in the third round.

"Obviously today was not the way I had planned to win," she said. "I feel sorry for Elina; I hope she gets well very soon."

Medvedev had two match points at 5-4 in the third set, but Borges forced a fourth set only to fade away as the Russian pulled away for victory.

"The third set was tough physically because he was playing very aggressively," Medvedev said. "As soon as I would hit one shot that was not aggressive or deep enough, he would just go full power. It was pretty impressive. After the third set, I just hoped it would not be five sets, and I'm glad it wasn't."

Later Monday, men's No. 2 Carlos Alcaraz bids for a place in the last eight when he plays Miomir Kecmanovic of Serbia.