The term will be added to other sentences Reece Wereta is currently serving at Otago Corrections Facility.
The 32-year-old appeared in the Dunedin District Court last week after pleading guilty to two assaults and injuring by an unlawful act.
The three victims were Pak'n Save employees working at the Hillside Rd business on the afternoon of January 10.
Wereta was in the car park waiting for his two female friends.
''He was heavily intoxicated after consuming alcohol throughout the past two days and nights,'' a police summary said.
His friends were followed out of the store by a 62-year-old staff member, who suspected they had been shoplifting.
The loss prevention officer confronted the group and Wereta immediately lashed out.
He pushed her on the shoulder and again with more force, sending her backwards on to the ground, where she struck her head.
The defendant and his associates continued walking towards King Edward St with two more supermarket employees in pursuit.
When they reached Glasgow St, Wereta threatened to ''smash'' the two men.
They refused to back off and the defendant responded by shoving one of them.
As the man staggered backwards and regained his balance, the drunk defendant followed it up with a kick to the stomach.
Wereta then approached the other man and punched him in the face before he and the women fled.
The female victim suffered concussion and a badly bruised thumb, the court heard.
She spent three weeks away from work, suffered fatigue and missed out on sports trips due to her injuries.
It was two months before she regained her health, Judge Thomas Ingram said.
He noted Wereta had ''a heap'' of previous convictions, but there were only two instances of violence among them.
Defence counsel Campbell Savage said his client had recently become a father and was motivated to change, since he had not seen the child outside a prison setting.
