Elina Svitolina in tears after back injury forces Australian Open withdrawal

The former world number three, who has made a very impressive return following the birth of daughter Skai last year, appeared the favourite to make the final from a wide-open top half of the draw.

But her back locked up in the first game of the match and she sobbed as she called it a day trailing 3-0.

She said: "This one I think I never had that before, the shooting pain like this. I had some injuries to my back before where it just was tiredness the next day of the match, but this one was really out of nowhere. I felt like someone shot me in the back."

Svitolina, who reached the semi-finals of Wimbledon last summer, did not want to think about what might have been, saying: "I cannot say that this was an open draw in a way.

"If you take other players, they are meant to be there. You have also in the other side of the draw very strong players who won slams and played really consistent throughout the year last year.

"So I don't want to look at this as a missed opportunity, especially right now when it was not about my tennis today."

Having beaten Iga Swiatek in the third round, 19-year-old Noskova is now through to her first grand slam quarter-final, where she will take on another Ukrainian in Dayana Yastremska.

She saved two set points in the opening set and then came from 3-0 down in the second to beat two-time former champion Victoria Azarenka 7-6 (6) 6-4, powering 38 winners.

Yastremska was ranked as high as 21 in 2020 but had not won a slam match since serving a provisional doping suspension the following year and had to come through qualifying here.

The 23-year-old tested positive for the synthetic testosterone mesterolone and missed nearly six months of competition before it was decided she bore no fault or negligence and was therefore free to compete again.

Yastremska is the second Ukrainian through to the last eight after Marta Kostyuk, and Svitolina will be cheering on her countrywomen.

"Of course I've been following that we all have been playing really well," she said. "At the beginning of the tournament, seven Ukrainians in the main draw, and going that far so many of us, it's nice in the second week as well.

"It's great for Ukrainian tennis. Of course, now I feel very old because of my health, but I'm happy that they are doing great. It's great for Ukrainian tennis. It's great for the upcoming generation as well, especially now these days when Ukraine is in such a tough time."

Yastremska, who fled Ukraine at the start of the war after spending two days in an underground car park, did not acknowledge Belarusian Azarenka at the end of the match.

"The last three years, a lot of things happened, but I'm not going talk about it right now," she said.

"A lot of things affected me, and because of that I couldn't really play like I wanted. Plus I put a lot of pressure on myself, as well.

"The war, of course, it's affected us a lot, because you cannot go home like you wanted, when you wanted like it was before. You always read the news. You always see the videos.

"As I said before, for example, when I was in Brisbane, the rocket arrived on my grandmother's house. It's tough emotionally to play, but the worst thing is you feel like you were already accepting this, what is happening. And people are starting to forget about what is going on."

Russian Anna Kalinskaya, who had won just four matches in 13 previous grand-slam appearances, is another player having a superb tournament, and she saw off 26th seed Jasmine Paolini 6-4 6-2.

Twelfth seed Zheng Qinwen restored some order, though, in the final match of the round, defeating France's Oceane Dodin 6-0 6-3 to make it back-to-back slam quarter-finals.