Amanda Anisimova has returned to tennis with new-found perspective and purpose - and that could spell trouble for defending Australian Open champion Aryna Sabalenka.
Fresh off a six-month mental health break, Anisimova continued her impressive comeback to take out practice partner and former world No.2 Paula Badosa in straight sets on Friday to be the first woman through to the fourth round.
The former teenage prodigy overcame some early serving woes and a big first-set deficit to carve out a 7-5 6-4 third-round victory on John Cain Arena.
The victory vaulted the 22-year-old into the second week at Melbourne Park for the third time, backing up her efforts from 2019 and 2022.
After reaching the French Open semi-finals as a 17-year-old, then making the quarters at Wimbledon in 2022, Anisimova took a hiatus last May citing mental health issues and burnout fears for the break.
The time out has worked wonders.
"It's quite unbelievable," she said of her latest Open charge.
"After taking some time off, I'm feeling really good and the most important thing is that I'm enjoying my time out here.
"Taking a step away and just really being at home and resetting myself; it gave me a different perspective going into these tournaments.
"I'm really trying to be present when I'm here. Having that is a huge advantage for me now."
Playing on her special ranking of No.61, despite slipping officially to 442nd in the world, Anisimova shapes as a huge last-16 threat to Sabalenka.
The Belarusian world No.2 quickly followed the American into the fourth round with a merciless 6-0 6-0 win over Ukraine's Lesia Tsurenko.
Sabalenka needed just 52 minutes to march on, and has dropped only six games in three one-sided victories en route to the second week.
"I'm just super-happy with the level I'm playing so far and hopefully I can just keep going like that, or even better," she said.
Sabalenka and Anisimova will clash for a place in the quarter-finals on Sunday.
With a 4-1 winning record over the titleholder, including victories over Sabalenka at the Australian and French Opens, plus another prized scalp in Melbourne in 2022 of two-time champ Naomi Osaka to her credit, the grand slam giant-killer isn't feeling overawed.
"I'm really happy that I was able to get this far, but I can do more," Anisimova said.
"(Sabalenka) is an amazing competitor. She's had a great year. I know she's going to be coming in hot, playing well. So I'm expecting a really good match.
"We're both very big hitters, so it always ends up being an enjoyable match to watch and also for us to play.
"I'm really looking forward to it."
Like Anisimova and Sabalenka, reigning US Open champion Coco Gauff is also through to the last 16 without having dropped a set after crushing fellow American Alycia Parks 6-0 6-2 in 61 minutes.
Fourth-seeded Gauff will play Magdalena Frech for a quarter-final berth after the Pole ousted Russian qualifier Anastasia Zakharova 4-6 7-5 6-4.
Russian teenager Mirra Andreeva staged the comeback of the day, rallying from 5-1 down in the deciding set to deny Frenchwoman Diane Parry 1-6 6-1 7-6 (10-5) in a match tiebreaker.
The 16-year-old will play Czech ninth seed Barbora Krejcikova, who ended local hope Storm Hunter's terrific run with a 4-6 7-5 6-3 win on Rod Laver Arena.
