''I can't sleep. I wake up every half an hour with flashbacks of what happened,'' Brett Greenheld says.
About 7pm, the 21-year-old walked out of a Kaikorai Valley lock-up he and his friends use as a car workshop and found three men waiting for him.
''I got held down, kicked, punched and stabbed,'' he said.
''I was stabbed twice in the chest and once in the top of the head and cut all over the face.
''I thought I was going to die.''
He needed 17 stitches as a result of the wounds, which were caused by what he thought was a box-cutter.
''My whole face was covered in blood,'' he said.
''It was pouring out of my head.
''When I ran back back into the workshop, I half-covered the floor [in blood].''
The attackers ran away and he was able to call a friend, who alerted police.
Since the attack, Mr Greenheld said he had been frightened about returning to the scene.
''Every time I go down to the workshop I get the shakes,'' he said.
He did not know the attackers but was able to get a close look at them.
''Two were Maori with quite solid builds, with black hoodies on ... and there was one white skinny guy.''
He thought the attack might be personal but ''I don't have a grudge against anyone and they don't have a grudge against me''.
''I haven't done anything to anyone.''
They did not speak during the attack but laughed as they ran away.
Sergeant Dean Pearce, of Dunedin, said police were reviewing security camera footage of the incident and called for any information the public might have.
It was ''quite a nasty assault'', he said.
Mr Greenheld was in a lot of pain after the attack and ''still very sore''.
Anyone with information about the attack can contact Dunedin police on (03) 471-4800 or anonymously on 0800 555-111.
