No. 1 Iga Swiatek exits Australian Open in a 3rd-round loss to Czech teenager Linda Noskova

Already down a set and facing a break point against Iga Swiatek, No. 50-ranked Linda Noskova decided she had nothing to lose.

She won 11 of the next 12 points to take the second set and swing momentum in their third-round match Saturday, ultimately becoming the first teenager to beat a No. 1-ranked woman at the Australian Open since 1999.

With a big serve and equally big groundstrokes, she unsettled Swiatek and held her cool, even under pressure in the last game to serve it out, for a 3-6, 6-3, 6-4 victory that means there are no top 10 players in the top half of the draw.

“I’m just really kind of exhausted mentally and physically,” Noskova said in her post-match news conference following the upset. “I just believed my game tonight. I just really wanted this.”

Swiatek is a four-time major winner but has never been past the semifinals at Melbourne Park. Even so, she was on an 18-match winning streak and expected to account for the 19-year-old Noskova, who is making her main draw debut at the tournament.

Swiatek beat 2020 Australian Open champion Sofia Kenin in the first round and had to rally from 4-1 down in the third to overcome 2022 finalist Danielle Collins in the second.

But after taking the first set against her Czech opponent, she struggled for rhythm. The decisive break was in the seventh game of the third set, with two forehand errors costing Swiatek the game.

Two games later, she held at love and forced her rival serve it out, then jumped to 0-30 lead in the 10th game.

But Noskova won the the next four points to finish it off quickly, including an ace to set up match point. She'll next play Wimbledon semifinalist Elina Svitolina.

Swiatek said the tough opening matches didn't hurt her.

“Physically I felt — honestly, I didn’t feel anything. So pretty good,” she said. “Mentally, as well, I felt like actually I came back in my match against Danielle, and I could kind of start over and not expect a lot, just try to play my game.

“I felt like I had everything under control until she broke me in the second set,” the 22-year-old Pole added. "Sometimes, yeah, I was rushing it. I just wasn’t playing kind of with my intuition and naturally.”

Swiatek's loss leaves No. 12 Zheng Qinwen as the highest-ranked player and two-time Australian Open winner Victoria Azarenka as the only past major winner in the top half of the draw.

Defending champion Aryna Sabalenka, seeded second, U.S. Open champion Coco Gauff, seeded fourth, and No. 9 Barbora Krejcikova are all on the opposite half.

The men's draw remains stacked, with No. 2 Carlos Alcaraz, No. 3 Daniil Medvedev and No. 6 Alexander Zverev having straight-set wins Saturday to reach the fourth round. Top-ranked Novak Djokovic, No. 4 Jannik Sinner and No. 5 Andrey Rublev already reached the last 16 on the top half of the draw.

Medvedev beat Felix Auger-Aliassime 6-3, 6-4, 6-3 and finished 2 1/2 hours before midnight local time. His second-round match finished close to 4 a.m. Friday.

He will next play Nuno Borges, who upset No. 13 Grigor Dimitrov 6-7 (3), 6-4, 6-2, 7-6 (6).

Wimbledon champion Alcaraz was leading 6-1, 6-1, 1-0 when the 18-year-old Shang Juncheng retired in the third set.

“It’s not the way you want to move on,” said the 20-year-old Alcaraz, who missed the 2023 Australian Open because of injury. “Last year I was watching the matches from my couch, wishing to be in the second week."

Alcaraz will play Miomir Kecmanovic, who saved two match points before upsetting 2023 semifinalist Tommy Paul 6-4, 3-6, 2-6, 7-6 (7), 6-0.

No. 9 Hubert Hurkacz beat No. 21 Ugo Humbert 3-6, 6-1, 7-6 (4), 6-3 and will play another Frenchman next, wildcard entry Arthur Cazaux.

French Open finalist and No. 11 seed Casper Ruud lost 6-4, 6-7 (7), 6-4, 6-3 to No. 19 Cam Norrie.

Azarenka won back-to-back women's titles here in 2012 and '13. On Saturday, she took out 2017 French Open winner Jelena Ostapenko 6-1, 7-5.

She trailed 5-2 in the second before winning five straight games.

“I’m just ready to give whatever it takes," she said. “I’m going to stay out here as long as it needs to be.”

Azarenka’s next opponent will be Ukrainian qualifier Dayana Yastremska, a 6-2, 2-6, 6-1 winner over No. 27 Emma Navarro.

Anna Kalinskaya beat 2017 U.S. Open winner Sloane Stephens 6-7 (8), 6-1, 6-4 to set up a meeting with Jasmine Paolini. The 26th seeded Paolini advanced 7-6 (1), 6-4 over Anna Blinkova, who was coming off a big upset win over 2023 finalist Elena Rybakina in the longest tiebreaker in women’s Grand Slam history.

In the Rod Laver Arena opener, Zheng, a U.S. Open quarterfinalist last year, edged fellow Chinese player Wang Yafan 6-4, 2-6, 7-6 (8) to reach the fourth round in Australia for the first time and a match against Oceane Dodin of France.

Zheng told the crowd she was motivated by watching Li Na win the Australian Open title in 2014 and was surprised to see later that her tennis inspiration was on site to watch the match.