The portrait depicts Margaret Fink, a pivotal figure in the resurgence of Australian cinema during the 1970s.
Best known for producing the 1979 film My Brilliant Career, she has also worked on films including The Removalists, For Love Alone and Candy.
Self-taught artist Mr Stathopoulos said Ms Fink, who is now in her early 90s, was a spirited sitter.
“Margaret proved to be a lively and stylish subject, and she was every bit as spirited as she presents in the final painting,” he said.
A tour guide from the Art Gallery of New South Wales told Mr Stathopoulos that the late actor Sam Neill, who starred in My Brilliant Career, had been spotted admiring the portrait.
“I’m delighted viewers have responded so positively with the work,” he said.
SAM artistic director Danny Lacy said the portrait had captured visitors’ imaginations through its realism and intricate detail.
“It’s a powerful work that draws you in, as demonstrated by its clear popularity with our visitors, many of whom have shared their astonishment with the painting’s realism and lifelike detail,” he said.
The announcement comes with less than two weeks remaining to see the Archibald at SAM, which is the exhibition’s only Victorian showing.
The Archibald Prize 2026 features 59 portraits from Australia’s prestigious annual portraiture award and will remain on display until Sunday, November 1.
Tickets are available at sheppartonartmuseum.com.au