Police reportedly believe the apparent attacker - who was apprehended by members of the public yesterday in a tense CBD showdown - slashed the woman's throat with a butcher's knife.
According to the Daily Mail, detectives are currently going through the victim and the perpetrator's phones to establish the nature of their relationship.
While the man was reported to be shouting religious slogans, the Daily Telegraph is reporting that he is 'believed to be an escaped mental patient'.
Vision captured at the scene shows a man on top of a car at a city intersection, waving a knife, before he falls to the ground as the car moves away. He is later heard asking to be shot.
Police were dispatched to King and Clarence Streets in the CBD, but it is believed members of the public detained the man ahead of their arrival.
Later vision, shown by Seven News, depicts the man pinned under a café chair by multiple men. A distressed witness at the scene is heard admonishing the man for ‘stabbing a chick’.
The alleged perpetrator is shown with blood on his hands and is seen relatively motionless, pinned under the chair with a milk crate over his head.
The man has yet to be charged.
WATCH: The Police Commissioner discusses yesterday's events