Unheralded Czech teenager Linda Noskova has shocked World No.1 Iga Swiatek in a stunning Australian Open upset.

Swiatek’s surprise defeat on Saturday night was first time since 1979 that the tournament’s top-seeded woman was knocked out before the fourth round.

Noskova is also the first teenager to defeat a world No. 1 at the Open since Amelie Mauresmo got the better of Lindsay Davenport in 1999.

Swiatek claimed the first set against world No.50 Noskova and appeared poised to claim her 19th consecutive win and progress her campaign at Melbourne Park.

But the 19-year-old Czech, who’s making her main-draw debut this year, fought back and broke Swiatek in the third set before serving out brilliantly for the biggest win of her career 3-6 6-3 6-4 on Rod Laver Arena.

Swiatek’s search for a maiden Melbourne Park title goes on.

The 22-year-old, who has won at Roland Garros three times and the US Open once, reached the Open semi-finals in 2022 and was knocked out in the fourth round last year.

Iga Swiatek fights in the third round of the Australian Open. Photo: Getty

When asked what made Melbourne Park so difficult for her, Swiatek said: “Well, surface is quicker. That’s all I would say.”

“I felt like I had everything under control until she broke me in the second set.

“I had couple of chances to break her in second set and I didn’t use them. So that’s a shame.

“But when she broke me, she was kind of proactive. I wanted to do that as well later in the next games.

“Sometimes, I was rushing it. I just wasn’t playing kind of with my intuition and naturally.

“I guess I’ll have to work on stuff to feel more comfortable next year.”

Swiatek’s defeat presents a golden opportunity for Elina Svitolina and two-time winner Victoria Azarenka — both on the Pole’s side of the draw — to make a deep run.

In the opposite bracket, defending champion Aryna Sabalenka and world No.4 Coco Gauff will be licking their lips.

‘Speechless’

Noskova will play Svitolina, who easily beat Viktorija Golubic 6-2 6-3, in the fourth round, once she comes down from Saturday night’s high point.

“I’m speechless,” Noskova said.

“I knew it was going to be an amazing match, with the world No.1, such a player, but I didn’t really think that it would end up like this.”

Linda Noskova has achieved the unexpected. Photo: Getty

It will be back to the drawing board for Swiatek, who took this defeat far better than her fourth-round exit last year, and admitted she’d struggled more than normal with her return of serve.

“Technically it didn’t work. But I know I did everything I could. I have kind of no regrets,” she said.

“For sure, I wish I could have played a little bit better in this tournament.

“This year I feel like I just want to get kind of back to work. I know I’m going to have plenty of chances during the season to show my game.

“Last year I felt like I was just overwhelmed with beginning the year as world No. 1. It kind of took me off my balance. It was totally different.”

Swiatek insisted tough opening matches against Sofia Kenin and Danielle Collins hadn’t affected her.

-with AAP