MELBOURNE: Giant-killer Amanda Anisimova, fresh from knocking out defending champion Naomi Osaka, will have world number one Ashleigh Barty in her sights when the Australian Open hits the last-16 stage on Sunday.
Meanwhile, Rafael Nadal, who says he is having "a very special week" after coming back from an injury-ravaged 2021, is one win away from the men's quarter-finals and a potential last-eight showdown with world number three Alexander Zverev.
But the whole of Australia will be watching their idol Barty to see whether she can keep the Melbourne Park party going in search of a maiden triumph to add to her Roland Garros and Wimbledon crowns.
The fearless 20-year-old Anisimova will be out to gatecrash the night-time festivities on Rod Laver Arena by claiming another famous win against Barty, who has only dropped eight games as she inches towards a maiden Grand Slam crown on home soil.
"It was a pretty good performance," said Barty, 25, after beating Italian Camila Giorgi 6-2, 6-3.
The top seed is now 7-0 for the season after winning the Adelaide warm-up event and in irresistible form. She has not lost her vaunted serve for 57 games over six matches.
Anisimova also sprang an upset with a second-round victory over Tokyo Olympic gold medallist Belinda Bencic and goes in buoyed by a famous come-from-behind win over Osaka.
"I just want to soak in this moment. I'm just extremely happy," said Anisimova after her stunning victory over Osaka, the 2021 and 2019 Australian Open champion.
Also in action is Victoria Azarenka, the Australian Open champion in 2012 and 2013, who will go up against world number four Barbora Krejcikova after the Belarusian turned back the clock to brush aside 15th seed Elina Svitolina in the third round.
Azarenka, after taking time away to have a baby, is aiming for a first quarter-final since 2016, but the 24th seed is not getting ahead of herself.
"I think that's really what I'm trying to say is that ladder I want to climb step by step," she said.
Krejcikova, the French Open champion, overcame a big fright against 2017 Roland Garros winner Jelena Ostapenko and then declared her never-say-die attitude meant her rivals should now be afraid of her.
"I hope they are scared of me," said the 26-year-old, who was one of the standout players of 2021, winning three titles as she soared more than 50 places up the rankings.
Other women's last-16 matches on Sunday see unseeded American Madison Keys, in form after her win in a Sydney warm-up event, eyeing an upset of eighth seed Paula Badosa of Spain.
And fifth seed Maria Sakkari of Greece faces another American, Jessica Pegula.
In the men's draw, Nadal, who dropped a set for the first time in the tournament before powering past Russia's Karen Khachanov, faces unseeded Adrian Mannarino.
The Frenchman will need to recover from a 4hr 38m marathon third-round 7-6 (7/4), 6-7 (4/7), 7-5, 6-4 win against Russia's Aslan Karatsev that did not finish until 2:32 am on Saturday.
The winner will face either Olympic champion Zverev, yet to drop a set, or 14th seed Denis Shapovalov of Canada in a signature quarter-final on Tuesday.
Other men in action include Italian seventh seed Matteo Berrettini against Spanish 19th seed Pablo Carreno Busta.
Flamboyant 17th seed Gael Monfils, unbeaten this year after winning a warm-up event in Adelaide, is yet to drop a set and comes up against Serbia's Miomir Kecmanovic.
The ageless 35-year-old Frenchman is targeting a second quarter-final appearance at Melbourne Park and the first for six years.