NSW has recorded day two of zero community COVID-19 transmission.
There were six cases diagnosed, all returned travellers in hotel quarantine.
"It is pleasing that we don't have any community transmission overnight," Premier Gladys Berejiklian said.
"But we do need to be on our guard."
She said complacency was the biggest risk and despite a jump in testing on Tuesday, called for testing numbers to be higher across the state.
There were 16,759 tests reported in the 24-hour reporting period, compared with 7,616 in the previous 24 hours.
"If people don't come forward and get tested, we can't keep the pandemic at bay," a NSW Health statement said.
"We would like to see testing levels above 20,000 as achieved last week."
The last time NSW had consecutive days without community transmission was at the start of July, while September 7 was the last case recorded with an unknown source of infection.
NSW Health is treating 74 COVID-19 cases, including three in intensive care, one of whom is being ventilated.
The news comes as South Australia plans to lift border restrictions for NSW residents from Thursday.
The long-awaited decision on SA's border with NSW was made at Tuesday's meeting of the state's transition committee and came after initial plans to lift the isolation measures were stalled for weeks because of a cluster of coronavirus cases in Sydney.
"This is going to be a relief that will be felt across our state, from an economic perspective and from a family perspective," Premier Steven Marshall said.
"We know that this has been a massive burden on the business community and also on families and individuals."
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