An underground rapper from Queens was busted this week on robbery and gang-assault charges, with cops claiming he helped rough up a guy he thought was someone else — and then beat up the man’s buddies after they came back to see what happened, police sources said.

Rapper Anthony Patria, 22, attacked the victim with two pals on Nov. 18 at the El Patio bar in Jamaica, sources said. Patria was taken into custody Thursday by detectives from the 103rd Precinct and arraigned but unable to post his $30,000 bail.

The self-proclaimed Trinitarios gang member has over half a million plays on SoundCloud and YouTube, where he raps about the group’s violent exploits. Patria can also be seen donning the gang’s colors in his videos and profile pics.

“I’m from Corona Queens 95th side,” he comments under one video, titled “IMMA TRIBU.”

“I’m put Corona on the map,” he adds.

Sources told The Post that Patria and his pals set upon the victim at El Patio around 3:30 a.m. after mistaking him for someone else. The man, nicknamed Elvis, later came back with two friends of his own, who were looking to see what happened.

“Sorry,” one of Patria’s pals told them, according to the sources. “You were the wrong Elvis.”

The answer didn’t sit well with the victim, and things quickly escalated. A fight allegedly broke out, and Elvis’ buddies were both given their own beatdowns at the hands of Patria and his goons, who also stabbed one of them, sources said. Sources said the group also swiped $200 in cash, some jewelry and a pair of sneakers — gold-tipped Jordans.

Sources said the rapper’s friends were still being sought by police Friday.

Patria’s arrest comes less than two weeks after the bust of Tekashi 6ix9ine, another New York-based rapper.

Tekashi, who is from Bushwick, Brooklyn, is looking at a maximum sentence of life in prison thanks to an alleged connection to an offshoot Bloods street sect known as the Nine Trey Gangsta Bloods — which has resulted in federal racketeering and firearms charges. He is also 22 years old.