A young man needed hospital treatment after suffering a serious assault as he opened the door of his home.
Police Scotland said the suspect ran off after the attack in Cross Road, Paisley at 10.30pm on Friday.
The 18-year-old victim was left with a laceration to the back of his head and was taken by ambulance to Royal Alexandra Hospital.
He cannot recall a description of the suspect and police are appealing for witnesses to come forward.
Detective Constable Stephen Gourlay of Paisley Police Office said: “We understand that this was a targeted attack.
“Enquiries are ongoing into the circumstances surrounding this incident and officers are studying CCTV images in an effort to gather more information.
“In the meantime, we are asking those who were in the area to contact police if they noticed anything suspicious around this time.
“It’s a busy residential area around Cross Road. If you can recall any disturbance around the time of this incident please contact police.”
Anyone with information can contact Police Scotland on their phone number 101.