The Australian can usually expect a febrile atmosphere when he plays on his favourite court, but a local coronavirus outbreak and unseasonably cold weather kept many punters away.
Those who did turn up were treated to some vintage Kyrgios moments - a racket thrown across the court.
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.
An out-of-sorts Kerber made the quarter-finals of the warm-up Grampians Trophy in Melbourne, organised for players forced into a hard 14-day quarantine on their arrival in Australia.
Nadal is looking to edge ahead of Roger Federer who also has 20 Slam titles to his name, with the injured Swiss not playing in Melbourne. He plans to return to the ATP Tour at Doha next month.
"It's tough to say because it can both be negative and positive," said the Russian, whose best Slam performance so far was making the final of the 2019 US Open.
Yet, for once, Djokovic may hear the rumbling of hooves as the likes of Austrian Dominic Thiem and Germany's Alexander Zverev look to storm the fortress.
Djokovic won his eighth Australian Open title last year and finished the COVID-19 pandemic-blighted 2020 season with the top ranking for a sixth year.
Simona Halep is the only woman over the age of 24 to have won a Grand Slam singles title in the last two years.
While Osaka played only four tournaments last season, Barty holds the top ranking despite playing her first competitive matches in almost a year in the Australian Open warm-ups this week.
Top seed Wawrinka, who sent down 14 aces and converted four out of seven breakpoint chances in the match, will continue his bid for a first ATP crown since winning in Geneva in 2017 and takes on local favourite Alex Bolt on Thursday.
Seventy-two players are currently confined to their rooms in Melbourne ahead of the Feb. 8-21 Grand Slam after positive cases were discovered on three flights ferrying them to Australia.
Sousa said he tested positive for COVID-19 before his departure but has since returned a negative test and is asymptomatic.
Barty reached the semi-finals at Melbourne Park for the first time last year before sitting out most of the rest of the season at home because of the COVID-19 pandemic.
They can think whatever they like. If they expect me to win the tournament, then that's their expectations.
At the end of isolation the players are scheduled to participate in tune-up events from Jan. 31 at Melbourne Park before the Feb. 8-31 Grand Slam at the same venue.
Now I feel more positive about it and I'm trying to do the most I can do to get out of quarantine.
Djokovic reportedly asked for reduced isolation periods and having players in hard quarantine moved to "private houses with tennis courts", drawing a backlash from Australians.
My good intentions for my fellow competitors in Melbourne have been misconstrued as being selfish, difficult and ungrateful.
The coronavirus pandemic is showing no signs of slowing down, with infections surging past 94 million and more than two million deaths, and Europe among the hardest-hit parts of the world.
"Obviously at this point, they are not going to get on-court preparation. But we'll access that, we'll work with each of the players to see what is best.
The former world No.1 is reportedly in good health and isolating at his residence in Surrey.
The three-time Major champion had been due to fly down to Australia this week to complete a two-week quarantine Down Under before the first Grand Slam of the season on February 8.