Mr Andrews said large-scale sporting events would operate as a "workplace" rather than an "entertainment venue". That means necessary staff can attend, but spectators cannot.
The Australian Open released a statement on Friday afternoon saying: "Tennis Australia continues to work with the government to ensure the healthy and safety of everyone.
"We are notifying ticketholders, players and staff that there will be no fans onsite at the AO for five days, commencing from Saturday 13 February.
"Full refunds will be available for anyone who has tickets for these sessions and they will be advised on how to apply as soon as possible."
Tournament director Craig Tiley told reporters players, their support staff and essential personnel will still be allowed on site as stars compete in a bubble format for the next five days.
"I know it's not the place that we wanted to be in," Mr Andrews said. "However, we've all given so much, we've all done so much. We've built something precious, and we have to make difficult decisions, and do difficult things, in order to defend what we've built.
"I am confident that this short, sharp circuit breaker will be effective.
"We will be able to smother this. We will be able to prevent it getting away from us.
"I want to be here on Wednesday next week announcing that these restrictions are coming off, but I can't do it on my own. I need every single Victorian to work with me, and with our team, so that we can run this to ground and we can see this strategy work."
Mr Andrews said he has to assume the virus is spreading at "light speed".
"We may find that, because of the contact tracing that we've already done, because of these sorts of charts and the thousands of hours of work that's gone on these last 10 days or so, that we don't have this problem," he said.
"The challenge is I can't wait a week to be proven right in that. We have to assume, based on advice, that there's transmission out there that we don't know about, and that it's not moving quickly, it's moving at light speed.
"And unless we make these decisions and limit movement in a short, sharp circuit breaker event, then we may be here in a week, regretting that we didn't follow that advice.
"That's not the way we've operated, and it won't be the way that we ever operate."
The first week of the Australian Open had been largely void of Covid scares after it had dominated the lead-up.
Seventy-two players were forced into a hard 14-day lockdown after arriving in Melbourne when separate people on three charter flights which brought players in from across the globe returned positive tests.
There was another major scare days out from the tournament when a staff member at a hotel used to house players tested positive and 600 players and officials were told to isolate and get tested.
Order was restored when all tests came back negative but Tiley has a new headache to deal with after the latest development.
3.55pm: Serena Williams advances
Serena Williams was looking in all sorts during her match against Anastasia Potapova but she was saved by the Russian's nerves.
Serving for the first set at 5-3, Potapova hit five double faults to hand her rival a break and keep Williams in the set.
The veteran took full advantage of the choke, winning the opener in a tiebreak – but the tennis was anything but pretty.
Tennis writers Christopher Clarey and Ben Rothenberg both described the action as "ugly" as Williams produced 18 unforced errors in the first seven games alone – more than what she delivered in her first two matches at Melbourne Park.
Tennis reporter Tumaini Carayol tweeted: "What a strange set. Even at the end, Serena looked like she has no confidence on her strokes. She finished it just hitting up the middle with added topspin.
"Potapova was the aggressor but she could not keep the ball in court on important moments."
However, the second set was a vastly different story. Williams was like a different player as she discovered her brutal best, thumping Potapova to wrap up a 7-6 6-2 victory.
2pm: World No 1's injury mystery deepens
Ash Barty and her doubles partner Jennifer Brady have withdrawn from the doubles competition.
No Information has been given besides their opening match result being recorded as a walkover.
Yesterday the Australian was heavily strapped at the thigh as she struggled to beat compatriot Daria Gavrilova.
Insisting she was "fit as a fiddle" the world No 1 was coy afterwards when asked about the taping.
She faces Ekaterina Alexandrova in the third round tomorrow.
1pm: Fresh virus scare in Melbourne
Covid-19 has already impacted the Australian Open significantly, but amid reports of an imminent lockdown in Melbourne, what happens to the tennis tournament?
Authorities fear Victoria is on the brink of the third Covid-19 wave with high-level discussions on Thursday night underway regarding the introduction of a snap lockdown.
State government advisers were on Thursday instructed to draw up a framework for another lockdown, which could be introduced as early as Friday night, or possibly within days.
Tennis Australia CEO Craig Tiley has already endured a nightmare scenario in the lead up to this year's tournament after 72 players were forced into hard lockdown after arriving in Melbourne.
Three charter flights returned positive Covid tests forcing stars and their entourage into strict quarantine.
One player – Paula Badosa – contracted the virus prior to the tournament. She was knocked out in the first round.
Ticket holders for this weekend's action have taken to social media questioning if their passes will be refunded should a lockdown ben announced.
Tennis Australia and Tiley have been contacted for comment.
12pm: Nadal targeted by heckler
In case you missed it last night, Rafael Nadal was interrupted during the second set of his win over Michael Mmoh when a fan heckled him from the stands.
She flipped him the bird and yelled out before security came and escorted her out of Rod Laver Arena.
The Spaniard wasn't sure what to think but found the whole situation funny, cracking up with laughter.
Nadal shrugged off the heckling before beating American qualifier Michael Mmoh 6-1, 6-4, 6-2 in the second round of the Australian Open.
The 20-time major champion completed the match against the 177th-ranked Mmoh in 1 hour, 47 minutes and said it was a "positive evening for me".
Except for one thing. He was asked if he knew the woman who caused the delay. He responded by saying no and added "honestly I don't want to know".
More than 21,000 fans attended Melbourne Park on Day 4.
The Australian Open is the first major in a year to allow sizeable crowds with the government allowing up to 50% capacity.
No fans were allowed at the US Open because of the Covid-19 pandemic and the number of spectators at the French Open was extremely limited.
Schedule
Rod Laver Arena
From 1pm
Aryna Sabaleka (BLR) [7] v Ann Li (USA)
Anastasia Potapova (RUS) v Serena Williams (USA) [10]
Adrian Mannarino (FRA) [32] v Alexander Zverev (GER) [6]
From 9pm
Veronika Kudermetova (RUS) [32] v Simona Halep (ROU) [2]
Novak Djokovic (SRB) [1] v Taylor Fritz (USA) [27]
Margaret Court Arena
From 1pm
Marketa Vondrousova (CZE) [19] v Sorana Cirstea (ROU)
Garbine Muguruza (ESP) [14] v Zarina Diyas (KAZ)
Grigor Dimitrov (BUL) [18] v Pablo Carreno Busta (ESP) [15]
From 9pm
Denis Shapovalov (CAN) [11] v Felix Auger-Aliassime (CAN) [20]
Iga Swiatek (POL) [15] v Fiona Ferro (FRA)
John Cain Arena
From 2pm
Su-Wei Hsieh (TPE) v Sara Errani (ITA)
Ons Jabeur (TUN) [27] v Naomi Osaka (JPN) [3]
Aslan Karatsev (RUS) v Diego Schwartzman (ARG) [8]
Not before 9pm
Dominic Thiem (AUT) [3] v Nick Kyrgios (AUS)
How to watch
You can watch the action live on Sky Sport, or stream it via Sky Sport Now.
