Fearless Ukrainian qualifier Dayana Yastremska surged into a maiden Grand Slam quarter-final Monday, stunning two-time champion Victoria Azarenka at the Australian Open.
Driven by a booming serve and aggressive groundstrokes, the athletic 23-year-old battled past the Belarusian 7-6 (8/6), 6-4 on Rod Laver Arena.
Her reward is a clash with unseeded Czech Linda Noskova, who progressed to the last eight when Ukraine's Elina Svitolina retired with a bad back while trailing 3-0 in the first set.
"I need to take a little bit of time to breathe because my heart I feel is going to jump out of my body," she said.
"I always felt like I was running behind the train, but I think because I am a little bit of a fighter that's why I won this match."
Yastremska's previous best at the Slams was a fourth round appearance at Wimbledon in 2019, but she has been in impressive touch at Melbourne Park.
Ranked 93, she has beaten a number of top 50 players, including Wimbledon champion and seventh seed Marketa Vondrousova in the first round.
She landed the first blow in a rollercoaster opening set, going up 3-1, but 18th seed Azarenka responded to put it back on serve as Yastremska's error-count ballooned.
Her veteran opponent then broke again to move 4-3 ahead, but faltered badly serving for the set at 5-4, blown away to love.
Another break gave Azarenka a 6-5 advantage, but she again lost her nerve, with Yastremska saving two set points before sending it to a tie-break, where she prevailed after 74 draining minutes.
Azarenka flew 3-0 up in the second set, but her serve was again exposed and Yastremska came storming back, with a searing backhand down the line giving her a second break for 4-3 and she never relented.
Emotional Svitolina retires injured
Elina Svitolina retired in tears from her Australian Open fourth-round match against unseeded Czech player Linda Noskova after just three games on Monday.
Svitolina, the 19th seed in Melbourne, needed a medical timeout at 2-0 down in the first set, during which she received treatment on court for her lower back.
The Ukrainian, 29, attempted to continue on Margaret Court Arena but was not moving freely and appeared to be in significant discomfort as her serve was broken for a second time.
The former world number three decided she could not carry on and walked to the net to concede.
Noskova, ranked 50 in the world, is enjoying a breakout tournament, including a stunning win against world number one Iga Swiatek in the third round.
"I feel sorry for Elina and hope she gets well soon," said the 19-year-old, who will play Ukrainian qualifier Dayana Yastremska in the last eight.