About 1,000 demonstrators gathered in the suburb of Richmond after the location of the protest was changed at the last minute to evade authorities, AP reported.
There were minor scuffles as well as a violent confrontation involving a handful of protesters. Several protesters were arrested.
Most of the demonstrators defied regulations by failing to wear masks.
Some 2,000 police officers were deployed at road checkpoints and barricades, and on roving patrols, to try to stop the rally going ahead in breach of public health orders.
Melbourne’s 6th lockdown began on Aug. 5. Melbourne is the capital of Victoria State, which on Saturday reported 535 new infections and one COVID-19 death in the latest 24-hour period.