A Hamilton woman attacked her teenage son while he was at work after he missed his curfew and she saw a lovebite on his neck.

Huia Dawn Te Pou, 32, admitted the November assault when she appeared in Hamilton District Court on Friday and was fined $200 and sentenced to six months supervision, the Waikato Times reported.

Te Pou became violent after spotting the lovebite on the 15-year-old's neck, her lawyer Len Caley said.

She pushed him out the back of the Grandview Mall, where he worked in a supermarket, and punched him in the face and chest.

Te Pou then dragged the boy back through the store and sat on him out the front of the mall to stop him escaping.

Witnesses called police who found Te Pou holding her son against a fence. He had blood on his head and looked dizzy, the court was told. The boy has since moved in with his grandparents in Rotorua.