A 26-year-old man suffered a fractured skull in a "senseless" unprovoked attack in Invercargill early Saturday morning.
Police said the local man was walking with two friends along Dee St, near the corner of Don St, when he was seriously assaulted about 3.20am.
Acting Senior Sergeant Ben Butterfield said the attacker, who was unknown to the victim, punched the man once, causing him to fall heavily to the ground.
"The victim has suffered a skull fracture with bleeding on brain," he said.
The man was taken to Dunedin Hospital where he remains in a stable condition.
"Police are appalled by this senseless act of violence and are requesting the public's help in identifying the offender," Mr Butterfield said.
The offender was described as a balding Caucasian man in his 40s or 50s, of stocky build, with a ginger and white beard.
Anyone with any information was asked to call Detective Tim Cook of Invercargill police on 03 211 0400 or Crimestoppers, anonymously, on 0800 555 111.
