Around 11.25pm the 52-year-old parked and exited his car on Campbell Street when he was approached by two men and a woman.
He was struck to the head and had property was stolen from him.
The three then made off along the lane from Young Street, passing Wishaw Academy Primary School.
The victim sustained a head injury and was taken to Wishaw General Hospital for treatment.
The first male suspect is described as being in his mid 20s and was wearing black clothing with a scarf round his face.
The second is described as being in his mid 20s, of medium to stocky build, with red hair.
The female suspect was wearing dark clothing and had long dark hair in a ponytail.
Officers are also keen to speak to a cyclist who was using the lane around 11.30pm that evening.
Detective Constable Karen Murray at Wishaw CID said: “We’re conducting a number of inquiries in the area as part of this investigation and would urge anyone who may have witnessed this, or who has information which can help, to get in touch.
“Those with information can contact Wishaw CID via 101 or, alternatively, call CRIMESTOPPERS on 0800 555 111 where details can be given in confidence.”