Naomi Osaka set to plummet to 84th in the rankings following Australian Open loss to Amanda Anisimova

Naomi Osaka is maintaining a brave face after blowing two match points in a gut-wrenching Australian Open defeat that will send the former world number one spiralling down the rankings.

As if relinquishing her Open crown wasn't painful enough, Osaka is projected to plummet to a scarcely believable 84th in the world following Friday night's tense 4-6 6-3 7-6 (10-5) third-round loss to Amanda Anisimova.

Osaka looked in tears after departing Margaret Court Arena but was upbeat in her official post-match press conference at Melbourne Park.

«I'm not God. I can't win every match,» she said.

«I think this for me is the biggest step — even though I lost, I think I was really focused throughout the entire match and I didn't have a dip.

»So that's really good, you know.

«Hopefully as the season continues, I'll be able to keep this up, and get even better at it.

»For me, I feel like I grew a lot in this match. The last match I played in New York, I had a completely different attitude."

The Japanese superstar only returned to tennis this month from a mental break after the US Open in September.

Ash Barty will face Amanda Anisimova in the last 16 after the unseeded American ended Naomi Osaka's Australian Open title defence.

She withdrew from the French Open after refusing to do any media and then missed Wimbledon altogether.

The four-time major winner also admitted the pressure of being the face of the Tokyo Games might have been too much, Osaka falling short in her quest to medal after lighting the Olympic cauldron.

But the 24-year-old looked mentally refreshed when she arrived in Melbourne, and loomed as Ash Barty's biggest title threat.

Pre-tournament, Osaka described the Open as the «sunshine slam» and was looking to get her career back on