Australian Open 2021 Results: Wednesday Bracket Winners, Scores and Top Stats

For the first hour of competition Wednesday, it looked like Rafael Nadal would cakewalk his way into the semifinals of the Australian Open having won the first two sets of his match with Stefanos Tsitsipas in convincing fashion.

Then came a third-set tiebreaker, won by Tsitsipas. And then a fourth set captured by the world's No. 5. Nadal would still keep things close in the fifth set, bringing it to 6-5. But with momentum on his side, Tsitsipas finished things off, knocking the second-ranked player from competition.

The Greek would become just the second person (Fabio Fognini in 2015) to defeat Nadal after falling two sets down in a Grand Slam match.

"I don't know what happened after the third set. I was flying like a little bird," Tsitsipas said during his on-court interview moments after the extraordinary comeback.

The 22-year-old now advances to the semis, where Russian Daniil Medvedev awaits.

"He's playing very well and is in good shape. I know he is going to give me a difficult time on the court," the Greek said of his semifinal opponent after the match, per David Zita and Fox Sports.

Tsitsipas has a 1-5 head-to-head record against the world's fourth-ranked player.

Men's Scores

No. 4 Daniil Medvedev def. No. 7 Andrey Rublev, 7-5, 6-3, 6-2

No. 5 Stefanos Tsitsipas def. No. 2 Rafael Nadal, 3-6, 2-6, 7-6(4), 6-4, 7-5

The oppressive 86 degree heat inside Rod Laver Arena, and a dazzling performance from No. 4 Medvedev, proved costly for seventh-ranked Rublev in the day's other quarterfinal.

"I mean, first of all, Daniil was playing—I mean, at least against me, if we take all the matches that I've played against him, today he played his best level," Rublev said, per Fox Sports Australia.

Medvedev added: "We always laugh about him, that he's like a battery, like Duracell or something. I actually managed to get him tired."

The world No. 4, who has yet to lose a match to his compatriot, said in his on-court interview just following the match: "We're all so competitive that during the match, you can see that nothing matters. You just need to win. So far, I think my game matches his quite well. I know how to neutralize his amazing big shots. That was definitely one of the best matches I played lately, not only here. I think he was playing really good."

On his latest loss to Medvedev, Rublev told Matt Fitzgerald of Tennis.com: "We're going to play, I hope, for many, many years, so at least once I think I will have a chance (laughing)."

While all eyes were on Rublev and the obvious effect the heat was having on him, Medvedev hid considerable cramping.

"I had to not show it. I managed to make some big serves and then at the end, it locked completely," he said, per Fitzgerald.

Medvedev, winner of 19 straight matches, will have time to recover before squaring off with Nadal in the tournament semis.

Women's Scores

No. 22 Jennifer Brady def. Jessica Pegula, 4-6, 6-2, 6-1

No. 25 Karolina Muchova def. No. 1 Ashleigh Barty, 1-6, 6-3, 6-2

Either No. 22 Brady or No. 25 Muchova will compete in the first Grand Slam final of their career at the Australian Open after respective three-set victories Wednesday night.

American Brady knocked off friend and former doubles partner Jessica Pegula, coming back from a first-set loss to put the daughter of Buffalo Bills owner Terry away. Brady's 4-6 loss in the first set represented the only one she has lost in this tournament to date.

Brady won the last six games to advance to the semifinals. It was the latest triumph on a journey that began with her and 71 other competitors undergoing two weeks of quarantine before the tournament began.

"Mentally I was feeling a little bit fried [before arriving in Australia]," she said after the match, per Joel Drucker of Tennis.com. "I think I used that two weeks to kind of reset mentally and also physically, just give myself, my mind, my body a little bit of a rest."

The rest obviously helped, and the Harrisburg, Pennsylvania, native now enters a showdown with Muchova, who knocked off the top-seeded Barty, ending any aspirations the Aussie had of lifting the Open championship in her home country. 

Muchova came back from a one-sided first set to defeat Barty, but not before taking an injury timeout that raised a few eyebrows.

"I started feeling a bit lost by the end of the first set. Ash started very good, she played almost like no mistakes, it was very tough. And I was a bit lost on the court, and my head was spinning (with dizziness) so I took a break," she said, per CNN's Ben Morse.

Barty, saying all the rights things, saw no problem with the 10-minute break: "It's not my place to comment here whether she had an injury or not. That's the physios and the doctors. Obviously that she's taken her medical timeout meant that there was something wrong. She was within the rules, within the guidelines to take that time."

Muchova and Brady have met just once before, a 7-6 third-set victory for the Czech player. "She's crafty," Brady said, per Drucker. "She looks to move forward. Has an all-court game. She's really athletic."

The winner of their battle Thursday will meet either Naomi Osaka or Serena Williams in the final of this years' Open.