A young woman needed hospital treatment after she was assaulted and seriously injured as she walked home in Rutherglen.
The 20-year-old was walking along Rowantree Avenue at about 0600 BST on Sunday when she was attacked.
A man approached her from behind, knocked her to the ground and attacked her with a sharp object.
She was taken to Glasgow's Victoria Infirmary and later discharged after treatment to lacerations on her back.
Strathclyde Police have appealed for information about the incident.
Det Sgt James Munro said: "This was a very serious attack and has left a young woman badly injured and extremely distressed.
"The surrounding area where the incident took place is a residential area and although the attack happened about 6am on Sunday, I'm hoping that someone may have seen or heard something which could help our investigation."