For her coach, Patrick Mouratoglou, there's no comparison between Williams's achievements and those of Court, who won 13 of her titles when tennis was still an amateur sport.
The Japanese third seed swept past the American veteran 6-3, 6-4 on Rod Laver Arena in front of thousands of fans allowed back in after Melbourne lifted a snap five-day lockdown.
"We look forward to welcoming fans back to the Australian Open for the next four days and to finishing the event safely and on a high," tournament director Craig Tiley said in a statement.
The Japanese three-time Grand Slam champion overcame the Taiwan world number 71 unorthodox style 6-2, 6-2 in an all-Asian quarter-final at a crowd-less Rod Laver Arena.
The see-saw contest continued in a tense decider with Osaka unable to convert a break point in the fourth game only to subsequently drop her serve and slam her racquet to the ground in frustration.
Kvitova, the former Wimbledon champion and Melbourne runner-up in 2019, committed 44 unforced errors in her 6-4, 1-6, 6-1 defeat to Romania's Sorana Cirstea.
Osaka, whose flashy attire included leggings and pink shoes, skirt and wristbands, won the first four games and continued the momentum as she relentlessly worked Pavlyuchenkova around the court with powerful groundstrokes.
"There was a lot of things I was struggling with, and I feel like during quarantine I really had to dig deep in myself and try to figure it out for myself."