Victorian authorities are confident the state's vaccinated economy system is working, after two positive cases from the Melbourne Cup were identified within days.
The state recorded another 1343 COVID-19 infections and 10 deaths on Friday, with the health department now managing 18,952 active cases.
The Victoria Racing Club confirmed on Friday that two people who attended Melbourne Cup Carnival events at Flemington Racecourse had tested positive.
A contractor who worked at the racecourse on Derby Day and Melbourne Cup Day, and a patron who attended Cup Day, are infected with a large contact tracing effort now underway.
Both cases are fully vaccinated and not linked to each other, with Stakes Day still scheduled for Saturday.
About 10,000 people attended the Melbourne Cup on Tuesday, including 500 members of the general public, after Victoria's public health restrictions were eased to allow events.
Health Minister Martin Foley said the outbreak showed Victoria's vaccinated economy system is working.
"VRC's systems have clicked into place pretty seamlessly ... Identified people early, the system of tracing and tracking through the VRC's own efforts has kicked in," he told reporters on Friday.
"I'm confident that punters can head along to the races tomorrow with great certainty that they'll be safe.
"More importantly, as our events and other measures start to kick in, the model that we've seen in the vaccinated economy will continue to work."
VRC said the contractor worked two full days in The Arbour in the purple zone on the ground floor of the Club Stand, while the patron attended the deck bar within the green zone on Cup Day.
The two venues have been deep cleaned and will be ready for safe operation at Saturday's event.
The racing club will send text messages to all patrons and staff who visited the deck bar, with all others not considered to be at risk.
The state government has announced Victoria's struggling health system will receive $307 million to free up capacity in hospitals and ambulances, due to a surge in demand.
There are 634 people in hospital, of whom 109 are in intensive care including 73 on a ventilator, while the seven-day average is at 681.
The health department is under pressure to release the total number of patients in ICU, after it was revealed only infectious ICU patients are being reported in the daily virus numbers.
Austin Health chief executive Adam Horsburgh said health authorities monitor currently infectious ICU patients and cleared patients who are no longer infectious, but the latter are not reported in the daily figures.
"We can certainly look at the potential to report those numbers," he told reporters.
Meanwhile, Victoria and NSW have reopened their borders to each other for the first time in six months, after all remaining orange zones were downgraded to green under the permit system.
Travellers and workers can now enter Victoria without testing or quarantining, including unvaccinated people, as long as they hold a permit to verify they are not COVID-positive or a close contact.
Fully-vaccinated Victorians are permitted to travel into NSW for recreation or holiday, unless they have been to a place of high concern.
More than 66,000 tests were processed on Thursday and 14,255 vaccines administered at state-run hubs, while about 82 per cent of people in the state aged over 12 are fully vaccinated.