There was no room for sentiment as Karolina Muchova Czech-mated her quarantine hitting partner Karolina Pliskova to send the former world No.1 crashing out of Australian Open at Melbourne Park.
Pliskova copped a point penalty for smashing her racquet during a toilet break of her shock 7-5 7-5 loss on Saturday.
Muchova battled back from 5-0 down in the second set to produce one of the upsets of the tournament against the much-fancied sixth seed.
"I'm a little sad because we are very good friends," said Muchova, the world No.27.
"But it's a game and I'm definitely happy that I made it through in two sets.
"We were both a little nervous, but I'm happy I'm through."
With Victoria in a five-day lockdown following another COVID-19 outbreak, the Melbourne Park stands were eerily empty as the Czechs took to Rod Laver Arena.
The opening set was tight but Pliskova looked to have found her groove before dramatically collapsing.
Muchova will meet Elise Mertens on Monday for a place in the last eight after the Belgian trounced Swiss 11th seed Belinda Bencic 6-1 6-1.
Elina Svitolina continued her quiet progression through the draw to advance to the fourth round without dropping a set.
The Ukrainian fifth seed had too many guns for Yulia Putintseva, winning 6-4 6-0 in one hour, 23 minutes after trailing 2-0 early.
Down 4-3 in the opening set, she reeled off nine consecutive games to win easily.
Like Bencic, Putintseva was among the 72 players forced into hard quarantine before the Open last month.
The 26-year-old was bizarrely accused of feeding rodents in her hotel after repeatedly taking to social media to complain of a mice plague in her hotel.
It has been quite the experience for her in Australia over the past month, but she will at least depart with a cheque for $215,000 for coming to the season's first grand slam.
"I know Yulia for a very long time. We used to play when we were kids - under 10s, under 12s - so I know her from a very young age," Svitolina said.
"So I always expect a big battle against her. She's a big fighter."
Svitolina will play Jessica Pegula next after the unseeded American crushed Frenchwoman Kristina Mladenovic 6-2 6-1.
Jennifer Brady, the American who'd been slated to play doubles with Ash Barty before Australia's world No.1 withdrew on Friday, also won through to the last 16.
Brady ended the run of Slovenian qualifier Kaja Juvan 6-1 6-3 and will play Donna Vekic next.
The Croatian staged a stunning fightback to eliminate giant-killing Kaia Kanepi 5-7 7-6 (7-2) 6-4 in a marathon match stretching two hours and 36 minutes.
Vekic trailed Kanepi - the second-round slayer of defending champion Sofia Kenin - and saved two match points after trailing by a set and 3-0 before mounting her fightback.
America's Shelby Rogers upset 21st seed Anett Kontaveit 6-4 6-3 and will meet world No.1 Ash Barty in the fourth round.
The Australian easily accounted for Russia's Ekaterina Alexandrova 6-2 6-4.
Barty defeated Rogers last week in a tough Yarra Valley Classic quarter-final, which was decided by a match tiebreak.
Australian Associated Press