Don’t call me Justin Bieber’s dad!”  A fuming JEREMY BIEBER shouted that warning just before exploding in a rage and beating his 20-year-old nephew to a bloody pulp at a Canadian bar, The ENQUIRER has learned exclusively.

The boozing-and-brawling Bieber clan turned a low-key Friday night at Dominion House bar in Stratford, Ontario, into a “boxing ring” on Jan. 13.

The singer’s 37-year-old dad, a former mixed martial arts fighter, was apparently drunk when he blew up. His sister Bonnie’s son Tylor set him off by saying that Jeremy was living off his famous son and “wouldn’t be anything if it wasn’t for Justin,” a family source told The ENQUIRER.

“Jeremy went ballistic! He started pushing Tylor in the chest, knocking him back and angrily telling him he wanted to be called by his own name, screaming, ‘I’m Jeremy Bieber!’

“Tylor knew the situation was out of control so he decided to leave the bar. But Jeremy followed him outside.

“Then wham! Out of nowhere, he grabbed Tylor by his coat and punched him really hard – right in the face. Tylor raised his arms to cover up, and Jeremy gave him three more blows to the head. He started bleeding everywhere.”

The battered youngster took off running. Meanwhile, Jeremy proudly strolled back inside, bought the whole bar drinks and started playing pool like nothing happened, said the source.

As The ENQUIRER previously reported, Justin’s largely absentee dad – who has a long criminal record and history of drug and alcohol abuse – never held a full-time job for long and makes money by selling autographed photos of the pop star on the Internet.

“Jeremy’s bar fights, temper tantrums and boozing are notorious,” said the source. “I think he’s nothing more than a drunken bully. He needs to get help.”