Only hours before their scheduled match on Saturday night, Osaka sprung a bombshell announcement by confirming she was withdrawing because of an abdominal injury.
"I've had to make the difficult decision to withdraw to address something my body needs attention for after my last match," the 28-year-old wrote on her Instagram story.
"I was so excited to keep going and this run meant the most to me, so having to stop here breaks my heart but I can't risk doing any further damage so I can get back on the court.
"Thanks for all the love and support ... I'm so grateful everyone embraced me so much.
"And thank you to my whole team for always having my back and the tournament organisers for being so kind."
Inglis, in her first major in four years, is through to the round of 16 for the first time to join Alex de Minaur as the only other Australian left in the tournament.
The Perth product will face world No.2 Iga Swiatek on Monday after the six-time major winner accounted for Russian Anna Kalinskaya 6-1 1-6 6-1.
"I haven't watched (Inglis's matches) but I saw from the scores ... she likes playing here as well," Swiatek said of her Australian opponent.
"It's exciting to be in a fourth round again.
"Hopefully you're not going to be so harsh on me, playing an Australian.
"A lot of Polish flags here, so please make it even."
One of two qualifiers to reach the last 32, Inglis spent 13 hours and 24 gruelling minutes over 14 sets to advance to the third round.
But with Osaka's withdrawal she avoided the oppressive heat in Melbourne on Saturday night.
World No.168 Inglis is guaranteed $480,000 by advancing to the fourth round.
18°C