Upsets and breakthroughs in early rounds of Australian Open

Muchova d. Linette 6-1 6-1

That was flawless from Karolina

She reaches the Australian Open R16 for the first time since 2021

The last time she reached the 2nd week here, she made it to the semifinals

✅6-1 in 2026

One of the most complete players in women’s tennis

🇨🇿❤️ pic.twitter.com/YuZDaAHTWK

— The Tennis Letter (@TheTennisLetter) January 23, 2026

In tennis, there are two kinds of upsets: the obvious, on-paper upsets--the "real" ones, and the upsets that dont really have anything to do with rankings. This past week, at the Australian Open, we saw our share of both in the early rounds.

In the opening round, 15th seed Emma Navarro, 26th seed Dayana Yastremska, and 30th seed Maya Joint were all defeated. Unseed, but highly skilled players who went out in the first round were two-time major champion Barbora Krejcikova, new Australian Daria Kasatkina, and Olympic silver medal winner Donna Vekic. 

Krejcikova--though it took her longer than it did some of her peers--has fallen victim to the Czech Curse, and has had a really hard time recoving from both illness and injuries; it wasn't a big surprise that she went out early. Nevertheless, it was disappointing to see her suffer another defeat. 

The most dramatic first round loss, though, was that of 20th seed Marta Kostyuk. The Ukrainian player had just played brilliantly in Brisbane, upsetting 2nd seed Amanda Anisimova, 8th seed Mirra Andreeva, and 4th seed Jessica Pegula before losing to Aryna Sabalenka in the final. Her outstanding Brisbane run gave Kostyuk quite a bit of  momentum coming into Melbourne, but it wasn't to be. In her opening round, she faced Elsa Jacquemot, and they played for three and a half hours. Kostyuk held a match point in the second set but couldn't convert it. Then, at 5-all, 30-0 in the third set, she fell and turned her ankle.

Kostyuk continued to play, but she was defeated 6-7, 7-6, 7-6. Upon learning that she had torn ligaments, Kostyuk withdrew from doubles competition.

In the second round, there was another dramatic upset: Czech qualifier Nikola Bartunkova defeated 10the seed (and recent United Cup MVP) Belinda Bencic, 6-3, 0-6, 6-4. (It should be noted that, in the first round, Bartunkova defeated Kasatkina.) The multi-skilled "everything on the Czech list" qualifier put on quite show against the multi-skilled Bencic, and became an early star of the tournament, though she fell to Elise Mertens in the third round.

Also going out in the second round were 24th seed Jelena Ostapenko, 25th seed Paula Badosa, 28th seed Emma Raducanu, and Maria Sakkari, who lost to Andreeva.

Former world number 1 Karolina Pliskova, who has been out for a year and a half because of injury and surgeries, returned to work in Melbourne and made it to the third round, which was impressive.  Pliskova lost to defending champion and 9th seed Madison Keys. Also of note in the third round--young Canadian star Vicky Mboko, seeded 17th, defeated 14th seed and tough opponent Clara Tauson. And young USA player Iva Jovic advanced to the round of 16 when she upset 7th seed Jasmine Paolini in the third round.

Meanwhile, top seed and two-time champion Aryna Sabalenka was put to an interesting test by Anastasia Potopova; Sabalenka prevailed, 7-6, 7-6. Also, two-time champion Naomi Osaka withdrew from the tournament because of injury, giving a walk-over to Australian qualifier Maddison Inglis.

Here is the round of 16 draw:

Aryna Sabalenka (1) v. Victoria Mboko (17)
Yulia Putintseva v. Iva Jovic (29)
Coco Gauff (3) v. Karolina Muchova (10)
Elina Svitolina (12) v. Mirra Andreeva (8)
Jessica Pegula (6) v. Madison Keys (9)
Wang Xinyu v. Amanda Anisimova (4)
Elena Rybakina (5) v. Elise Mertens (21)
Maddison Inglis (Q) vs. Iga Swiatek (2)

There has already been a major upset in doubles. In the second round, 2nd seeds Sara Errani and Jasmine Paolini lost to Australian wild cards Kimberly Birrell and Talia Gibson.