As the victim was checking patrons’ ID at the door, the defendant punched him without warning, breaking his left eye socket.
At Wrathall’s sentencing in the Queenstown District Court on Monday, counsel Tanya Surrey asked Judge Russell Walker to take account of the defendant’s youth and a health condition.
The defendant took medication that had combined with his heavy drinking on the night to ill effect.
The judge said a pre-sentence report found alcohol and drug use, and a propensity to violence, was behind the offending.
Wrathall had four previous convictions, one for assault with intent to injure in 2020.
Last year’s offending was aggravated by the attack to the head, causing a significant injury with long-term effects.
The victim, who had lost wages during his recovery, had been shocked by the “completely unprovoked” attack, and his mental health had been affected.
Judge Walker gave the defendant discounts for his guilty plea, youth and health condition, and for attending 12 positive lifestyle sessions with the Salvation Army.
He came to a sentence of 12 months’ imprisonment, which he converted to five months’ home detention at his mother’s home in Christchurch.
Wrathall must also pay the victim $500 reparation for emotional harm.