Lady Gaga played an intimate gig here on Sunday night with 92-year-old Tony Bennett, and that meant for one night only Bob Arum, at just 87, was not the oldest swinger in town.
Arum promotes Saturday's fight at the MGM between Tyson Fury and big Tom Schwarz, the latest heavyweights to fight under Arum's name as the old man of the ring continues his dominance of a business he first entered in 1966.
It stopped being about legacy and dollars decades ago for Arum on nights when the sport's greatest fighters made history, and Arum the institution he is. He has a few hundred million stashed away to prove it.
The first fight he promoted was Muhammad Ali against George Chuvalo in Toronto. Ali was in flight, refusing induction to the US military, and Arum, a lawyer educated at Harvard and formerly employed by the US Attorney's office as a tax expert, had to be nimble to keep the champion in business; Ali defended his title in three different countries in 1966 as he battled the government, storing up money for his imminent exile. Ali fought 25 times for Arum.
Arum has been witness to forgettable nights in apartheid South Africa, the illegal crossing of borders, long nights with Ali, armed guards on river boats in Yugoslavia, scuffles at ringside with Don King and fight after fight after fight.
He is the man who gave us boxing's finest piece of working jargon when he once told a pack of eager fight hacks: "Yesterday, I was lying. Today, I'm telling the truth." That is the boxing business.
His crown has been tilted, never removed, many times in over 50 years of confrontations, lawsuits, legal battles, government investigations, three marriages and actual fisticuffs.
His colleagues, fighters and rivals offer vivid testimony to his skills at negotiating and it can be unpleasant to read at times. He ripped King's jacket after the Marvin Hagler and Sugar Ray Leonard fight in 1987 and King pointed at a pistol as they struggled on the steps to the ring.
It was Bob's show and Don, merely a ringside guest, was trying to stage a coup at the end. Bob resisted that with force, forget the law books. Arum and King were, in an industry famous for hatreds, the most toxic of partners when forced to agree a deal for a fight.
It would go something like this, Arum joked: "Tell Bob this, King would say, and then I would say - tell Don this."
They made fights happen, they each knew and loved a deal.
"I admire Bob," King insisted. "I really do. But when you push that button, it doesn't matter if you are the Pope or the president - he is going to call you a dirty mother*****r."
King is also 87 and still active on the fringes of the boxing business. The pair were reunited, smiled and held up each other's hands a couple of years ago. It still looked fake.
There was also the clash with Donald Trump back in 1991 when the now president entered the winning bid to stage the Evander Holyfield and George Foreman fight in Atlantic City, next to his new and doomed casino. Trump refused to pay in full, claimed an act of war - the Gulf crisis - had sabotaged his financial planning and a new deal was created in the days before the fight to salvage the night.
"Trump owes me $2.5m from that deal," said Arum. "He always tells me that he feels bad about it - I always tell him he can still pay."
Arum never forgets a figure or a fight. Any conversation with Arum is as likely to turn to an obscure Donald Curry win, an all-Mexican epic or a new bit of Ali trivia as his sense of history and memory combine.
During the last 30 years, with Ali and Hagler long gone, Arum guided Oscar de la Hoya and Floyd Mayweather from skinny, wide-eyed kids to wealth and success, running their careers and companies. There were the many nights with Manny Pacquiao, a fighter raised from a wayward boxing kid to become one of the sport's giants by Uncle Bob. There are plenty still inside his orbit now, including both Vasyl Lomachenko and Terence Crawford, arguably the No.1 and No.2 in the world. And then there was the second coming of Foreman, out for a decade and then taken to glory by Arum in a resurrection that is still hard to grasp. Arum can, make no mistake, work magic in the fight game when he lets his lips and brain flow.
The Fury experiment is not some type of gamble at the end of the night for the promoter who has so far defied time.
"Fury is channelling Foreman and Ali," Arum said on Tuesday at the open training sessions. "He is boxing's entertainer - nobody in our business now is like him."
Arum is in no rush with Fury and Fury is in no rush with Arum. The recent Anthony Joshua loss suddenly made the crazed race to be recognised as the best in the world an irrelevance in many ways. Arum wants to make Fury the best known and most popular heavyweight in the world, a title more elusive and impressive than the slender glory that comes with a belt.
Arum is not a one-night only man, not like the beautiful Tony Bennett, hired for a few tunes to make Lady Gaga cry, and after Fury wins here on Saturday he will start making plans for New York later in the year. It will be Madison Square Garden, Fury fighting and Arum going nowhere fast at his side in the latest double act in boxing's longest encore.