"Members of the public were concerned by developments and some yelled at all of the men to take their gang problems elsewhere," the summary said.
The Mongrel Mob members retreated to a vehicle on Kuirau St by a children's playground but Fane followed.
"Fane raised a sawn-off .22 rifle and fired a single shot through the rear passenger window of the BMW ... The direction of the shot was directly towards the Mongrel Mob member, who was at the same time reaching into the front passenger seat of the car."
The bullet smashed a window and became lodged in the front passenger seat headrest.
Fane ran from the scene and escaped in a vehicle.
The other two defendants have pleaded guilty to disorderly conduct for their part in the events.
Judge Tony Snell sentenced Fane to three years and seven months' imprisonment on the unlawful discharge of a firearm charge, and four months on each of the two breach of bail charges, to be served concurrently.