Shannon Lestrange pleaded guilty to one charge of unlawful assault at the Ballarat Magistrates' Court on Monday.

Police prosecutor Senior Constable Steve Repac told the court Lestrange and the victim had been in a relationship but were now friends.

The court heard on October 3 Lestrange and the victim were drinking at his home with another friend when he head butted her to the middle of the forehead, causing dizziness.

Senior Constable Repac said the victim then walked into the kitchen where Lestrange grabbed her hand with a tight grip.

The court heard Lestrange let go, the victim grabbed her car keys and walked out to her car while Lestrange followed her without saying anything.

Senior Constable Repac said the victim received a text message from Lestrange when she arrived home that said 'I am sorry for what I did but you deserved it'.

The victim told police she had bruising to her forehead and had a headache for a number of days when she reported the incident to police on October 17.

Lestrange was served with an intervention order on October 18 and refused to be interviewed about the assault.

A safe contact order is now in place for almost two years.

Representing himself, Lestrange said he was not working and had not taken any steps to address his alcohol issue.

Magistrate Noreen Toohey sentenced Lestrange to a 12 month community corrections order with a requirement he engage with alcohol counselling and mental health programs.

"You have to start dealing with those issues or you will be back here time and time again," she said.

"By your plea of guilty you have demonstrated remorse. It is really important for you to get the assistance because there is a risk you will come back (to court) if you don't."