Elina Svitolina retired hurt early in the first set of her Australian Open fourth round meeting with Linda Noskova, while Victoria Azarenka was upset by Dayana Yastremska.
Svitolina was left in tears after she was forced to retire due to a back injury early in the first set, handing Czech teenager Linda Noskova a spot in her first Grand Slam quarter-final on Monday.
Meanwhile, Yastremska sent two-time champion Azarenka tumbling out as the 23-year-old Ukrainian prevailed 7-6 (7-6) 6-4 to book a spot in the last eight.
Svitolina had a medical timeout at 2-0 down and was trailing 3-0 when she decided to quit.
“Obviously today was not the way I had planned to win,” said the 19-year-old Noskova, who beat top-ranked Iga Swiatek in the third round. “I feel sort for Elina, I hope she gets very well soon.”
Qualifier Yastremska continued her fairy-tale run by knocking out 18th seed Azarenka.
The Ukrainian world No 93, who stunned Wimbledon champion Marketa Vondrousova in the first round, had to fight hard but was rewarded for her aggression with 38 winners to forge on into a half of the draw devoid of top 10 seeds.
“I feel like my heart is going to jump out of my body,” the 23-year-old said after the biggest win of her career.
“I was losing the tie-break, I was losing the second set, I was always felt like I was running behind the train. But I think I’m a little bit of a fighter so that’s why I won this match.”
Yastremska got the first of the six breaks of serve in the opening set only for Azarenka to rattle off the next four games to edge in front.
Azarenka, back-to-back champion in 2012 and 2013 and a Melbourne semi-finalist last year, served for the set but Yastremska kept up the pressure through five deuces and finally converted her fourth break point to force a tie-break.
That was just as tight but the Ukrainian sealed it with her 21st winner, a blistering forehand that was just too fast and too deep for 34-year-old Azarenka.
Both players took lengthy bathroom breaks after the first set and Belarusian Azarenka came out firing, racing to a 3-0 lead almost before Yastremska had time to catch her breath.
The Ukrainian stalled Azarenka’s progress and then went back on the attack, finding her rasping winners again to win five straight games.
She held her nerve serving for the match two games later, lashing across one more big backhand to set up a meeting with Czech world No 50 Noskova on Wednesday.
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