A man's been sentenced to two months community detention and 12 months supervision - after assaulting a Nelson dairy owner over a pack of cigarettes

Open Justice reports last November, 26-year-old Gabrielle Howard threw shop owner Suathi Lam to the ground, pushed her head, sat on top of her and kneed her in the stomach.

Lam followed Howard outside after his card declined and he tried leaving with the cigarettes.

Howard later admitted to multiple charges including theft and common assault saying he'd been in a drug-induced psychosis.

Judge Jo Rielly said in sentencing he'd made significant steps in rehabilitation since.