The American, who in May announced an indefinite break from the sport because of mental health concerns and burnout, kicked off her campaign in Melbourne by knocking out Russian 13th seed Liudmila Samsonova 6-3, 6-4.

Anisimova, a semi-finalist at the French Open in 2019 and former world number 21, followed that up with comprehensive victories over Argentine Nadia Podoroska and former world number two Paula Badosa in the next two rounds.

"I'm really proud of myself," Anisimova told reporters.

"I wasn't sure, should I expect to do well? Because a lot of people were telling me, 'don't put too much expectations on yourself. You've taken a lot of time off. Don't get too down on yourself if you don't do well at these tournaments'.

"I kind of took that in a little bit, but I still expected a lot out of myself. But at the same time I was going to be happy whether I lose in the first round or if I do well.

"I'm just really happy that I was able to get this far, but I still think that I can do more."

Currently languishing at 442nd in the world, Anisimova can expect a big bump in her ranking by reaching the Melbourne Park fourth round for the third time.

She will have to be at her very best to get any further, however, with in-form defending champion Aryna Sabalenka as her next opponent.