The new cases, which are all linked to previous cases in the outbreak, were detected from among 43,618 test results processed on Friday.
It is the highest single-day increase in local cases this year, ahead of 27 cases detected on 21July.
The number of exposure sites linked to the outbreak continues to grow, with supermarkets and a GP clinic among the latest locations added in Melbourne's west.
Authorities last night also flagged unexpected wastewater detections from the past fortnight across Balwyn, Camberwell, Canterbury, Mont Albert and Surrey Hills in Melbourne's east.
"Anyone who lives, works or has visited the above suburbs in Melbourne's east between 26 July and 4 August is urged to watch for the slightest of COVID-19 symptoms and get tested as soon as possible if any symptoms develop," health officials said.
So far, the recent outbreak has centred on clusters in the Hobsons Bay and City of Maribyrnong council areas in the city's west.
Health authorities are still trying to match the genomes from recent cases with a national database, with Health Minister Martin Foley flagging a possible link to a family who completed hotel quarantine in New South Wales.
But Foley has also warned that until vaccination thresholds agreed upon by National Cabinet are reached, lockdowns will continue to be the primary method for suppressing the highly transmissible Delta strain.
"Nobody likes lockdowns but as we've now established, they work," he said on Friday.
"They're one of our major tools in our public health response and until such time as we have the levels of 70 and 80 percent vaccination, they're going to continue to be a part of that toolkit."
Foley said the state government had "very forcefully" made a case to the Commonwealth to have the delivery of about 150,000 Pfizer doses brought forward in light of the outbreak.
There are now four schools caught up in the state's latest Delta outbreak, after the Islamic College of Melbourne revealed an infected person attended its campus last month.
In a statement on Friday, the Tarneit school said the local public health unit "could not identify an exact time the case was infectious" and so all staff, visitors and students were considered close contacts.
As a result, the entire school community must get tested immediately and quarantine until further notice, even if they receive a negative test result, the college said.
"The College urges everyone to stay safe and follow the official guidelines and instructions," the statement said.
The college is the fourth school in the city's west to be affected by the outbreak, alongside Al-Taqwa College, Heathdale Christian College and Warringa Park School, which is a specialist school in Hoppers Crossing.