A father-of-five punched a man who he believed had hit his son after the boy climbed on a unstable wall.
Kevin Firth, 35, of Platt Street, Blackpool, pleaded guilty to assault, being drunk and disorderly and breaching a conditional discharge.
Steven Townley, defending, said Firth’s son ran back home crying and screaming and said a man had whipped him with a wire.
Firth lifted up the boy’s T-shirt and saw a welt on his skin.
The matter of an assault on the boy was now being investigated by the police.
Firth was ordered to pay his victim £100 compensation and fined £180 with a £100 court charge, £20 victims’ surcharge plus £100 costs by District Judge Andrew Jebb sitting at Blackpool Magistrates’ Court.