Australia is being "cut off at the knees" by actions such as banning crowds at the Melbourne Cup, veteran horse trainer Gai Waterhouse says.
The Victorian government banned spectators at Flemington Racecourse for the 160th race that stops a nation, as part of its suite of measures to tackle the coronavirus pandemic.
It was the fourth consecutive day in Victoria with no COVID-19 cases and no deaths.
"We have to get on with it," Ms Waterhouse told 2GB radio on Tuesday.
"By all means social distance ... but you can't have the country cut off at the knees. People can keep their space, wash their hands, wear masks if they want to."
Victorian Health Minister Martin Foley said four days with no cases and only 38 active cases across the state was a "substantial achievement".
"The message that I have for the people of Victoria is of course, reflect and enjoy today ... but the price of a COVID-safe summer is eternal vigilance when it comes to following the rules."
Victoria's Commander of Testing Jeroen Weimar said there was a "long way to go", noting there was likely to be undetected cases of COVID-19 in the community.
"It's our job to be really vigilant."
NSW recorded one new locally acquired case of coronavirus.
The case was linked to a known cluster, and there were also two more infections among returned overseas travellers in hotel quarantine.
Queensland reopened its border to regional NSW residents for the first time in almost four months.
And South Australia announced it will relax its border restrictions in about two weeks, allowing people to quarantine at home.
The hard border closure with Victoria will be abandoned and people will be able to isolate for 14 days in a home environment rather than at a medical hotel.
Bars and restaurants across Melbourne were booked out as people forced to stay away from Flemington watched the Cup.
Tensions boiled over at an anti-lockdown rally at Parliament House in Melbourne.
Dozens of people were arrested and capsicum spray was used as police dispersed the demonstrators.
ACT Health issued a list of tips to help punters watch the Cup including to not "jockey with strangers" by maintaining 1.5 metres, reining in groups by not showing up to venues with extra people and to stay home if you have a hoarse throat.
Australians surveyed for a Guardian Essential poll remain happy with the way governments are navigating the coronavirus pandemic.
Approval of the Morrison government's response remains steady at 61 per cent.
Support for the Victorian government's handling of the crisis has climbed from 45 per cent to 55 per cent in the past fortnight, the most positive result since June.
Approval for Victorian Premier Daniel Andrews has also climbed from 54 per cent to 61 per cent.
Support for the NSW government and Premier Gladys Berejiklian also remains strong, with both measures standing at 68 per cent.
Two-thirds of voters in Queensland approved of Annastacia Palaszczuk's coronavirus response.