Victoria has recorded one new case of COVID-19 in hotel quarantine, as more than half the passengers potentially exposed on a Qantas flight have been cleared of the virus.
Of the 241 passengers on board QF778 from Perth, 135 have so far tested negative.
Four close contacts of a 54-year-old infected passenger on the flight - his spouse, two children and one child's friend - have also tested negative.
The man flew to Melbourne from Perth on Wednesday.
On Sunday, health authorities said contact tracing work was well progressed and messages had been sent to all passengers from the flight.
Of the 10 airport staff potentially exposed to the case, six have tested negative.
Victoria has not had any new local cases, making 58 days with no community transmission.
The state opposition leader Michael O'Brien told reporters on Sunday the state's result means its contact tracing systems have improved.
"It does appear now the government has learnt some of those lessons and that's a good thing and I welcome that.
"We don't want to see any new cases in Victoria, but when you have contact tracing that works, that's what you should be able to rely on," he said.
As Western Australia battles an outbreak, imposing a three-day lockdown, 42 people currently in Victoria have identified as having attended exposure sites in WA, and must quarantine for 14 days.
A total of 32 of those people have so far tested negative.
After playing at Perth's Optus Stadium at the weekend, North Melbourne's AFL side returned to Melbourne on Sunday.
All members of the party were tested on arrival and must isolate at home, but have been granted an exemption for training and on medical and compassionate grounds.