Maunder stayed in the car outside the home while his co-defendant went to the house.
The friend and the victim had an argument at the front door, which eventually turned into a fight on the street.
Maunder saw this altercation and left the car.
The court heard the co-defendant restrained the victim, holding his arms down, while Maunder delivered an upper-cut to the defenceless man’s face.
Photographs in the summary of facts showed the victim suffered a bruised face and a bloodshot eye.
Judge Duncan Harvey told the defendant he was “extremely lucky” the injuries were not worse.
“One punch is enough to kill someone,” he said.
The judge sentenced Maunder to 10 months’ home detention with judicial monitoring.
The co-defendant is still before the court.