A teenager assaulted a man outside a Huddersfield nightspot because he felt that he had insulted his friend.
George Gummerson, 19, admitted punching Daniel Howe several times after leaving the Camel Club.
Kirklees magistrates ordered him to pay hurt Mr Howe compensation.
The court heard that the incident happened late on April 20.
Mr Howe had decided to leave the Byram Court club and was followed by a group including Gummerson.
Alex Bozman, prosecuting, said: “Mr Gummerson made remarks suggesting that Mr Howe had been racist to one of his friends.
“That’s not accepted by Mr Howe but he (Gummerson) accepted that he punched Mr Howe in the face three times.”
The assault was witnessed by a customer in a nearby takeaway who reported it to police.
Mr Howe suffered a black eye and swollen nose and had a cut glued at hospital.
Gummerson also received hospital treatment after hurting his hand while he was hitting Mr Howe.
Any Day, mitigating, said that his fitness instructor client had felt provoked.
He told magistrates: “He felt he had to defend himself and his friend.
“That self-defence went too far and the amount of force used was unreasonable.
“He’s ashamed of himself.”
Magistrates gave Gummerson, of Kenyon Bank in Denby Dale, a conditional discharge for 12 months.
But he must still pay Mr Howe £100 compensation as well as £85 court costs and £15 victim surcharge.