He had an epically bad hair day.

A Bronx barber was beaten to a pulp by an irate patron wigging out over a lousy trim — and was then fired because the shop’s manager believed his employee started the brawl.

The longtime patron popped by the Diamond Cuts shop in Tremont at around 8:30 p.m. on Feb.16 but was so dissatisfied with the 53-year-old barber’s handiwork that he refused to pay.

Other workers at the shop offered to touch up the shoddy job, setting off the proud barber’s apparently hair-trigger temper.

“No, you’re not fixing nothing! I want my money!” the “aggressive” barber roared, the shop’s manager told The Post on Saturday.

But the customer refused to part with his dough. The coiffeur then “grabbed,” “shoved” and “swung” at him and yelled “I’m gonna kill you!” said the manager, who said he watched the wild scene unfold on surveillance video.

The client then grabbed a hairbrush and whacked the barber, police said.

The barber chased his customer outside, where he was met by two of the man’s friends — who joined the fray. A female suspect hit the beleaguered barber several times, while a second man — clobbered him with a baseball bat, authorities said.

All three suspects sped off in a white 2014 Nissan Altima with New Jersey plates, while the barber was rushed to St. Barnabas Hospital with an elbow fracture and was given 15 stitches near his left eye, cops said.

But the manager claimed the customer was acting in “self-defense” and canned the barber — who had only worked at the shop for three weeks.

“I saw [what happened], and I was so disgusted. You don’t do that,” he said. “We go by the old-school code: The customer is always right.”

Police are still searching for all the three suspects.

The Bronx fracas is the third incident against barbers in the last two weeks. George Thomas, 37, was busted for hurling a Molotov cocktail at El and John’s Barber Shop in Brooklyn on Feb. 17. And on Feb. 9, another hot-headed Brooklyn customer shot a Fifth Unisex Salon barber in the pelvis because he asked the man to stop bothering his customers.