A trio of Big Apple ticketmen took a lesson out of the Cosa Nostra playbook, when they viciously beat a ticket seller from a rival hop-on, hop-off tour bus company for refusing to switch alliances, a new lawsuit alleges.

Victim Pitoh Poyodi of The Bronx suffered facial fractures after being headbutted in the Sept. 15, 2018, broad daylight attack in what appears to be a larger ongoing turf war between the Big Apple’s double-decker bus tour companies.

Poyodi was working for Gray Lines when he was approached on a street corner in Midtown by TopView Sightseeing employees Abdul Yakubu, Lyuben Ivanov and Jonathan Hengal, according to the suit filed Thursday in Bronx Supreme Court.

The men allegedly asked Poyodi to join their crew, offering him money. But when he refused “several attempts” to get him to switch sides, Ivanov — a company director — allegedly ordered Yakubu to lay down some street vengeance.

Yakubu “viciously attacked” Poyodi, headbutting him and kneeing him in the abdomen beneath the Empire State Building on the corner of 34th St. and 5th Ave around 1 p.m., according to a police report and the court docs.

He was taken to NYU Langone for treatment for facial fractures and a groin injury.

Lawyer Brian Elbaum said the assault had saddled Poyodi with pricey medical bills and lasting trauma and he has been unable to return to work.

“There’s an ongoing issue relevant to competition between various tour companies in the city and it’s problematic. What my client suffered from is an example of that,” Elbaum said.

Yakubu was arrested by cops and charged with three counts of assault but a lawyer for parent company Go New York called the claims “bogus” and “baloney” and denied Yakubu was an employee.

Poyodi is suing Go New York for unspecified damages but the suit is just the latest in a flurry of legal action between the two companies.

In August, Go New York accused Gray Line of engaging in a “concerted, street-level campaign to defame, disparage and harass” their ticket sellers and customers, according to a complaint filed in US District Court.

Gray Line’s ticket sellers reportedly told prospective customers that TopView is “the worst company,” with “filthy and old” buses that “break down all the time.”

In another incident in June, Go New York claimed a Gray Line ticket agent threatened to “kill” one of their employees while a supervisor made a menacing neck-slashing motion to him in front of distressed TopView customers.

“There’s always fighting over territory around here, especially between us and Gray Line,” one TopView ticket gal told The Post on Tuesday.

“A few weeks ago I saw one of our guys get into it with a Gray Line guy. They were competing over customers and one of them disrespected the other. The next thing, they were beating the s–t out of each other,” she said.

“Cops had to come and break it up. It’s too bad because there’s enough tourists in New York for everybody, but some people get really competitive.”