The change follows a national cabinet decision that the states would no longer require a positive result on a rapid test to be confirmed via a PCR test.
Prime Minister Scott Morrison conceded there would still be lines at PCR testing centres for the next couple of weeks until supply problems with at-home tests were sorted out.
By about 8.20am on Friday, at least 16 PCR testing sites across Victoria were at full capacity and forced to temporarily close.
The closed sites included Victoria Universityâ€™s St Albanâ€™s campus site, the Bourke Street walk-in clinic in Melbourneâ€™s CBD, the Northern Hospital drive-through and walk-through sites, and Springers Leisure Centre at Keysborough.
Listed wait times at other sites varied from 30 minutes at facilities including the Aughtie Walk drive-through at Albert Park, to 180 minutes at St Vincentâ€™s Hospital.
Revised density limit rules also came into effect at 11.59pm on Thursday, with indoor hospitality venues, including restaurants, cafes, pubs and nightclubs, as well as other entertainment venues, such as gaming venues, now subject to a quota of one person per two square metres.
Another 68,202 COVID-19 tests were processed across Victoria on Thursday, while 20,726 people received a dose of a COVID-19 vaccine at a state-run clinic.
The proportion of the stateâ€™s population aged over 12 who are double-vaccinated stands at 93 per cent, while 13 per cent have received their booster shot.