Mr Weimar said the positive case - the only case found in Shepparton for that 24-hour period and one of just two in regional Victoria - was a primary close contact of a previous positive case, and had been in isolation.
The positive case came as Victoria recorded 324 new local cases of COVID-19 on Thursday - the highest daily total since August 2020 - with just 107 of those linked to known outbreaks.
Of the 324 cases, 102 were from Melbourne's western suburbs, 195 from northern suburbs, five from eastern suburbs, 20 from the south-east and one from an unidentified location, along with the two from regional Victoria.
The second regional case was from the Mitchell Shire, with regional areas - except for Greater Shepparton - to be freed from lockdown from 11.59pm Thursday night.
More than 37,000 people received a vaccine dose at state-run centres on Wednesday - another new record - while of 111 people hospitalised with the virus across the state, 89 per cent were unvaccinated and none were fully vaccinated.
As of Thursday morning, 63.2 per cent of eligible Victorians had received a first dose of a vaccine.
While the large increase in case numbers appears alarming, Health Minister Martin Foley denied regional Victoria's lockdown was ending too soon.
“The public health advice clearly had projections as to what was looking like the growing number of cases in metropolitan Melbourne,” he said.
“At the same time, we have seen higher levels of vaccinations in our regions, we have seen, as is the case in Shepparton, twice now, and in Mildura and Colac, there is a deeper sense of ownership and engagement in regional communities with their health services.
“That's not to say there isn't such a level of engagement in the city but it is deeper in the regions, and there is this sense of proprietary, ownership and support for their public health efforts.”
Asked what easing of restrictions could be allowed once 70 per cent of the population were double vaccinated, Mr Foley said Victorians should feel incentivised to come forward and be vaccinated.
“You can re-engage in commercial life, and social life, and cultural life, all of these things form part of the real incentive, to get out there and get vaccinated,” he said.
“More fundamentally, the motivation of looking after yourself and your family and protecting those you love, given the increasing levels of infection in the community, that’s the most important incentive, to go out there and get vaccinated.”