The senior Liberal's seat of Kooyong is the target of well-funded independent Monique Ryan, who has campaigned on climate action, the establishment of a federal integrity commission, safety for women and healthcare reform.
Mr Frydenberg was standing strong on Saturday.
"I've been really encouraged by the positive reaction I've had on prepoll the last couple of weeks, as well as meeting with constituents this morning," he told Sky News.
The Victorian Liberal Party lodged a complaint about Dr Ryan's campaign material, claiming unauthorised content including Chinese writing, and demanded its immediate removal.
"Correspondence from the AEC indicates that electoral communications you have authorised are in breach of the Commonwealth Electoral legislation," the major party said in a letter to Dr Ryan, made public on Saturday.
An official for Dr Ryan said: "All Chinese election campaign material used by Dr Ryan's campaign, including how-to-vote cards, are properly authorised in the correct languages".
The Liberal Party of Victoria dismissed the claims of the Ryan campaign.
"They have continued to hand out unauthorised How to Vote cards throughout the day in the full knowledge that they were not appropriately authorised," a statement said.
"Ms Ryan claims she was advised that they were appropriate (sic) authorised. Pigs will fly."
There was further controversy in the inner-southeast Melbourne seat of Higgins, where the Federal Court on Saturday ordered the removal of bright green campaign signs reading "put Labor last".
Labor claimed the signs were erected by Liberal campaigners and were aimed at confusing voters.
Former President of the Victorian Liberal Party Michael Kroger conceded the marginal Liberal-held seat was at risk.
"(Incumbent) Katie Allen has done a fantastic job as the member, but it's very close," Mr Kroger told Sky News.
He said independent candidates, dubbed 'teals', posed a significant challenge.
"Demographic changes, and we've got a big teal campaign in Goldstein on that side and a big teal campaign in Kooyong on that side, so it's going to be close," he said.
In Goldstein, Zoe Daniel is another independent hoping to take control of a long-held Liberal seat.
Ms Daniel, a former journalist, said her grassroots campaign had raised more than $1 million as she battles Liberal incumbent Tim Wilson, who has held Goldstein since 2016 with a latest margin of 7.8 per cent.
The electorate has been in Liberal hands since 1984.
If the election delivers a hung parliament, Ms Daniel pledged to work with whichever party could deliver on climate policy, integrity, gender equality and safety for women and girls.
"I would negotiate in good faith with both sides if it came to (a hung parliament)," she said.
"It's really up to the leaders of both major parties to decide what they want to put on the table."
Leader of the Greens Adam Bandt cast his vote alongside his family at Kensington Primary school in the seat of Melbourne.
Mr Bandt told the ABC he had received reports of people voting for the Greens for the first time, as they pushed for a change in government.
Mr Bandt holds the inner-city Melbourne seat for the Greens with a comfortable margin of 22.6 per cent.
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