World number one Iga Swiatek is out of the Australian Open after being stunned by Czech 19-year-old Linda Noskova in the third round.
The Pole, 22, had looked in control but the highly-rated Noskova fought back to win 3-6 6-3 6-4 on Rod Laver Arena.
In the decider, the world number 50's power rocked Swiatek, who was hampered by forehand errors.
"I'm speechless," said Noskova, who has reached the fourth round of a major for the first time.
"I knew it was going to be an amazing match with the world number one but I didn't really think it would end up like this.
"I'm just really glad to get through this round."
Noskova is playing in the main draw in Melbourne for the first time, having lost in qualifying last year as an 18-year-old.
She fell to the floor in disbelief after converting her first match point following a tight third set.
The loss also ended Swiatek's 18-match unbeaten run, which stretched back to September.
Swiatek's exit follows second-round defeats for third seed Elena Rybakina, fifth seed Jessica Pegula and sixth seed Ons Jabeur, with only three of the top 10 seeds - defending champion Aryna Sabalenka, US Open winner Coco Gauff and Barbora Krejcikova - left in the draw.
Noskova will play Ukrainian 19th seed Elina Svitolina next.
BBC