The 30-year-old confronted the 16-year-old in Pinniger Street, Yarrawonga, on Tuesday afternoon after he threw rocks onto a roof.

The boy headbutted the woman to the cheek and she grabbed onto him to steady herself.

The teenager pushed her into a tree and headbutted her two more times before leaving.

He was arrested about 200 metres away and had a knife on him.

The boy faced court on Wednesday and was refused bail, having been on bail at the time of the incident.

Sergeant Damien Loiterton said he had been charged with recklessly causing serious injury, recklessly causing injury, two counts of unlawful assault and possession of the knife. 

He said the woman had a suspected broken nose and possible cheek injury but police were awaiting medical reports. 

The boy, who did not know the victim, will return to court on Monday.

Any witnesses to the incident can contact police on (03) 5744 3641.