As the victim tried to crawl away, his attacker struck him with the metal object again before he managed to escape to his car, drive back to his workplace, and raise the alarm.
Police arrived and a guard was placed at the property overnight to allow a scene examination to be carried out.
"Cowardly attacks such as last night's have no place in Hamilton which has forged for itself a reputation of being the family friendly, event capital of the country," Mr Thornton said.
"It's therefore important that when incidents such as this occur those with information come forward and share it."
Anyone who saw anything suspicious in or around Montgomery Cres about the time of the attack or who has information on the identity of the attacker is asked to contact Detective Sergeant Shelley Begbie at the Hamilton Central Police Station on 07 858 6200.
Alternatively, information can be left anonymously with Crimestoppers on 0800 555111.