With Victoria back in lockdown as of midnight Friday night, residents from other states rushed to cross the borders as restrictions were tightened across the country.

Federal MPs in Melbourne were also urged to get to Canberra before midnight to avoid missing Parliament's sitting week beginning Monday.

Victoria's snap decision to reintroduce stage four restrictions for the next five days meant crowds at the Australian Open were sent home at 11.30pm to avoid breaking curfew.

While the interruption did not affect the match between US Open champion Dominic Thiem and Nick Kyrgios on Friday night, the Aussie was beaten in a tough five-set, third round loss.

Post-match, Kyrgios declared he wouldn't force himself to travel overseas and play under tough restrictions this year as the coronavirus pandemic dragged on.

"I just don't think it's right. I'm not going to force myself to play," Kyrgios said.

Just one new locally-acquired case was recorded in Victoria on Saturday, following on from five new cases in the state the day prior.

With Australia's hotel quarantine system once again under scrutiny, Victoria Premier Daniel Andrews said there needed to be a "cold, hard discussion" about reducing the number of travellers returning to Australia from overseas.

The case discovered in Victoria on Saturday was found to be a friend of a hotel quarantine worker, bringing the total number of cases linked to the Holiday Inn outbreak to 14.

Prime Minister Scott Morrison was in Melbourne on Friday to make a vaccine announcement, alongside Health Minister Greg Hunt, from the CSL laboratories.

Mr Morrison said he intended to leave Melbourne for Sydney following the announcement.

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