The woman was walking on Thames Boulevard after getting off a bus in Tarneit about 9.15pm on Wednesday night.
Detective Sergeant Sean Nicholson said she was approached by a man, who grabbed her chest, before attempting to drag her towards the road.
CCTV captured their struggle and the woman’s screams before she managed to break free from her attacker.
She was not physically injured.
Police said the man fled south towards Melpomene Boulevard.
Detective Sergeant Nicholson said the victim was “extremely distraught and distressed” from the incident.
He described the attack as “every woman’s worst nightmare”.
“It’s disturbing. You are simply walking home at a reasonable hour at night and then set upon by an unknown male,” Nicholson said.
“She was very brave in her reactions and quick and prompt, which no doubt saved anything further bad from happening.
“We are unclear of the motive at this stage of what the offender was trying to do. We are really trying to identify him and hold him to account so that any escalating behaviour is stopped.”
The offender is described as being in his late teens or early twenties, and was described as being 160cm tall with slim build and short dark hair.
Police are seeking to speak to the driver of a dark-coloured 4WD that was seen in the area at the time of the attempted abduction.
Anyone with information has been urged to come forward to police.