Katy Perry left a glitzy Las Vegas charity event, joking, “I am not going out J.Lo style,” as hell-raising oil heir Brandon Davis got into a scuffle with banana billionaire Justin Murdock.

Perry snuck out of hot new Vegas club 1Oak on Friday night after Davis got into a tussle with his arch-rival Murdock, the Dole fruit heir who famously nicknamed himself “Cobra McJingleballs,” according to a 2010 lawsuit from an ex-employee.

A spy said Perry, who was co-hosting the GiveLove charity event with J. Molinari Jewelry designers Markus Molinari and Jason Arasheben, “immediately got up when Brandon and Justin started arguing and pushing each other.”

The fracas started when Justin “stood too close to Brandon, who was with Petra Ecclestone’s husband, James Stunt. Brandon tried to shoo Justin away and Stunt’s bodyguard got involved. Then there were 10 security guards breaking it up.”

Another source said, “There were no punches thrown, it was just pushing and shoving. Katy immediately walked away. She joked to her friend that she wasn’t ‘going out J.Lo-style’ ” — referencing the 1999 Club New York shooting when Lopez was dating Diddy.

“Greasy Bear” Davis and McJingleballs have a history. In 2004, the two reportedly got into a fistfight outside the men’s room at Hollywood bar Guy’s.

Despite the scrapping scions, Perry seemed “in a good mood” as she attended the opening weekend of 1Oak at the Mirage. Spies said she “kept a low profile, sipped on cocktails and sat with her friend Markus.” Others partying with club owners Richie Akiva and Scott Sartiano included David Arquette, Paris and Nicky Hilton,
Scott Disick, Chris
Evans, Christina Milian and Shenae Grimes.

Murdock — again at 10ak on Saturday night along with Davis (without incident) — declined to comment. Davis’ reps did not respond.