Victoria's coronavirus cluster has grown to 54 active cases with an alarming surge in infections.
The state's health department on Saturday said 19 new locally-acquired cases had been reported.
All of Saturday's cases are related to current outbreaks.
Health Minister Martin Foley said 18 were out in the community while infectious.
“Our public health team is responding quicker than they ever have before because this virus is moving quicker than it ever has before,” he said.
“They identify not only those infected but those who may have come into contact and the next possible multiple layers of contacts after that.
“On average, each case, as I indicated earlier, has spent less than two infectious days in the community, and that measure is really important because it shows the value of going hard and going early to make sure that we get our arms around this as quickly as we possibly can.”
More than 47,000 tests were conducted in the past 24 hours.
The state also now has more than 160 exposure sites including last Saturday's AFL game between Carlton and Geelong at the MCG and Tuesday's rugby test match between Australia and France.
A full list of the exposure sites can be seen here.
Victoria remains in lockdown and at this stage is due to come out of it on Tuesday night.
Premier Daniel Andrews conceded earlier this week the lockdown could last longer than five days though.
"We've got no choice. We have to do this, otherwise, it will get away from us. We don't want this getting away from us and being locked down for months," he told reporters.
Victoria was placed in lockdown at 11.59pm on Thursday.
The same rules that applied during last month's lockdown have been reimposed, including a five-kilometre travel limit for exercise and shopping and compulsory masks indoors and outdoors.
The lockdown will end at 11.59pm on Tuesday, though restrictions in regional Victoria could be lifted earlier if it is safe to do so.
Concerns over fleeting transmission
Covid-19 commander Jeroen Weimar told reporters on Friday authorities are concerned about "very fleeting transmission".
Friday's cases included a man in his 20s from Point Cook, who attended an AFL match between Carlton and Geelong at the MCG, and was seated in the MCC Members' Reserve.
He is the fourth person to have contracted the virus from an Ariele Apartments resident, who attended the match with a friend from Barwon Heads.
The infected man unknowingly contracted the virus from a group of NSW removalists who had worked at the Maribyrnong apartment complex late last week.
He passed the virus on to his parents and his friend, a teacher at Bacchus Marsh Grammar.
Four men at the MCG who contracted the virus were not seated near the infected man, nor were they known to each other.
Mr Weimar said transmission most likely occurred when the infected man went to the bar or the toilet.
Another two new cases are linked to the Young and Jacksons pub in the CBD, which the infected man visited prior to the match.
The two cases - a Richmond man and a member of the defence force based at HMAS Cerberus - are strangers to the infected man and each other.
Bacchus Marsh Grammar has reported a total of four staff have tested positive, though this is yet to be confirmed by the health department and could be included in Saturday's tally.
Deakin University tweeted on Friday afternoon about a positive test in a staff member from its Waurn Ponds campus, though the government is yet to confirm it.
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