The attacker – who was carrying a knife- took his victim’s wallet from him. The suspect is described as being in his early 20s of slim build with short dark hair.
Detective Constable Lindsey McIntyre, Wishaw CID, said: “This appears to have been an opportunist attack and the man has been left severely shaken and with an injury to his head and face.
"This type of behaviour is completely unacceptable and it is vital that we trace the individual responsible.”
Anyone with information is asked to contact Wishaw CID via 101, quoting incident number 3557.