Defending champion Naomi Osaka also looked set for a win inside an hour against American Madison Brengle.

Japan's Osaka won the first set in 20 minutes but lost her way in the second before securing a 6-0 6-4 victory.

Another serving masterclass from Barty

As she aims to become the first home champion since 1978, Barty says trying to avoid coronavirus as rates rise in Melbourne has not affected her.

"For us, it's pretty low-key anyway," she said.

"We come and practice and do what we need to do. Otherwise a good book and a coffee and I'm set."

The two-time Grand Slam champion has not dropped a game on her serve at Melbourne Park this week, beating Bronzetti in 52 minutes to back-up another emphatic win in the first round.

On Monday, the 2021 Wimbledon champion dropped one game as she thrashed Ukraine's Lesia Tsurenko in 54 minutes.

Barty has started the 2022 season by winning all six of her matches, having lifted the Adelaide International title last week.

On the strength of her service game, she said: "I'm continually trying to make it a weapon.

"I'm not the biggest girl out there, but I know I've got a sound technique and I know if I can get my rhythm right and use it effectively, it can be a weapon.

"As a kid, I was always serving baskets and baskets of serves to try to create that weapon, try to create a really sound shot."

Osaka continues to thrive in Melbourne

Few players in the women's game - if anyone - are better than 24-year-old Osaka when she executes the power and precision which has led to four Grand Slam titles.

Those fans inside Melbourne Park for Wednesday's night session witnessed some fine ball-striking in the first set, which left Britain's Andy Murray impressed as he watched on the television.

After cruising through the first set, Osaka briefly lost her way midway in the second. Brengle finally got on the scoreboard - drawing great applause from Rod Laver Arena - before further stalling the two-time Melbourne champion.

Mounting frustration peaked for Osaka after she whacked a smash long to let Brengle break for 4-3, only for the 13th seed to instantly hit back.

Then she rediscovered a better level in the final couple of games to wrap victory in one hour and five minutes.

"I returned pretty well, that's not my usual stat but I've been really working on that in the off season," said Osaka, who took a four-month break at the end of last season.

"I'm trying not to rate my level, if I compare myself to the past I will never be satisfied. I'm trying to take it one day at a time.

Svitolina comes through 'rollercoaster' match

Harmony Tan was taken off court in a wheelchair after injuring her left calf against Elina Svitolina

Ukrainian 15th seed Elina Svitolina said it was "sad" to see her opponent Harmony Tan helped off court in a wheelchair during their second-round match.

France's Tan had fought back to take Svitolina to a deciding set before injuring her left calf.

She was trailing 6-3 5-7 5-1 when she attempted to serve out the final game of the match but was advised by the umpire to stop.

"It was a rollercoaster match," Svitolina said. "It's very sad to see her leaving the court in a wheelchair.

"It's never, never good to see a player getting injured."

Svitolina, long tipped as a future Grand Slam champion, will face two-time Australian Open winner Victoria Azarenka next after the Belarusian swept past Switzerland's Jil Teichmann 6-1 6-2.

Spanish eighth seed Paula Badosa saw off Italy's Martina Trevisan 6-0 6-3, while Madison Keys kept up her early season form with a 6-2 7-5 victory over Romania's Jaqueline Cristian.

Former French Open champion Jelena Ostapenko hit back to beat Alison Riske 4-6 6-2 6-4 and China's Wang Qiang battled to a 2-6 7-6 (7-5) 6-3 win over Alison van Uytvanck.

However, Olympic gold medallist and 22nd seed Belinda Bencic fell 6-2 7-5 to American Amanda Anisimova, who has yet to lose a match this season.