Victoria Police have released CCTV footage of the incident as they hunt the man, describing his actions as "predatory".

After the man grabbed her from behind, police said she elbowed him to the stomach.

He then tried to choke her and she bit him on the right hand.

"She's really, really shaken by this - she was petrified," said Detective Inspector Juliann Goldrick.

"This is extremely concerning, his actions - very predatory in the way he acted.

"His intention is quite possible one of a sexual crime or sexual assault."

The woman suffered no physical injuries and Det Insp Goldrick said she was "very brave" in how she handled the situation.

Det Insp Goldrick said the video footage of the incident was excellent.

"If you know him, you will know him straight away," she said.

The 25-year-old woman was walking along Glenferrie Rd in suburban Hawthorn around 1am on Sunday.

After she became aware that the man was following her, she crossed the road and went to Burwood Rd, where she called a friend.

A vehicle was seen driving slowly behind the woman before it passed her and then parked, with the man then walking to a side street.

As the woman passed, he grabbed her from behind and tried to drag her down the side street.

Two witnesses heard the woman screaming and chased the man as he ran away.

They briefly confronted him before he threatened them.

He was then seen on CCTV returning to his car.

The man is believed to be about 183cm tall, with a heavy build and pot belly, and he was wearing a black ski mask.

Australian Associated Press