A 52-year-old man was walking along Stonelaw Road in Rutherglen when a small white car drove up beside him and a man jumped out and assaulted him.
The victim suffered facial injuries in the attack, which happened at 11.20am on Friday, and was taken to the Glasgow Victoria Infirmary.
The suspect is described as white, around 5 ft 8 in with short dark hair medium build. He was clean shaven and in his 40s with a local accent. Police are appealing for information.