Victoria has recorded 21,728 new COVID-19 cases, while another six people have died and hospitalisations have again increased to 644 people.
With 68,202 people lining up for a PCR test, it means just under one-in-three people have tested positive in the latest 24-hour reporting period.
There are 58 active cases in intensive care and 24 on ventilation.
By 9am on Friday 18 state-run PCR testing sites had reached capacity and closed, compared to 35 sites at the same time on Thursday, as new rapid antigen testing rules came into force overnight.
The RATs have at times proved difficult to find, but it’s hoped their use will reduce pressure on the overloaded PCR testing system.
From 11.59pm on Thursday, Victorians who test positive with a RAT must isolate for seven days and notify their contacts.
They must also report the result to the state’s health department through an online form expected to go live on Friday afternoon, or alternatively over the phone.
The new category of “probable” cases determined by RAT are discouraged from confirming the result with a PCR test, unless they have no symptoms and are not a contact of a positive case.
Probable cases will receive the same clinical and financial support as PCR confirmed cases.
They will be reported alongside confirmed PCR test cases each day, once the system is up and running.
Restrictions are also being reintroduced, including density limits of one person per two square metres for indoor hospitality and entertainment venues.
Meanwhile, world No.1 tennis player Novak Djokovic has spent his first night in immigration detention in Melbourne, as he fights the cancellation of his visa ahead of the Australian Open.
The 20-time grand slam champion has launched legal action in a federal court to challenge the decision, and is waiting on a hearing scheduled for Monday.