Despite initially appearing in control, the 22-year-old Pole faced a determined challenge from the highly-regarded Noskova, ultimately succumbing 3-6, 6-3, 6-4 on Rod Laver Arena.
Noskova, ranked 50th globally, showcased her formidable power in the decider, capitalizing on Swiatek’s forehand errors.
This marks Noskova’s first main draw appearance in Melbourne, contrasting with her qualifying loss last year as an 18-year-old.
In disbelief, Noskova fell to the floor upon converting her first match point in a closely contested third set.
Swiatek’s exit not only concludes her 18-match unbeaten run since September but also follows early departures for third seed Elena Rybakina, fifth seed Jessica Pegula, and sixth seed Ons Jabeur.
With only three of the top 10 seeds remaining – defending champion Aryna Sabalenka, US Open winner Coco Gauff, and Barbora Krejcikova – the competition intensifies.
Next, Noskova is set to face Ukrainian 19th seed Elina Svitolina, building on her significant victories over Jabeur, Azarenka, and Daria Kasatkina on the WTA Tour last year.
This remarkable win establishes Noskova as the first teenager to defeat a world number one at a Grand Slam since Petra Kvitova’s triumph over Dinara Safina at the 2009 US Open.