TYSON FURY surprised everyone at Vasiliy Lemachenko's fight with Richard Commey at Madison Square Garden.
The Brit got into the ring and grabbed a microphone to start singing to Arum, who was celebrating 90 years.
Fury sings happy birthday to Arum at Madison Square Garden
Arum was treated first to the arena singing Happy Birthday. Then came an American Pie classic.
Oleksandr Usyk, WBA, IBF and WBO heavyweight champions, was also in New York to support his fellow countryman Lomachenko. He went on to easily defeat his opponent, and then called out undisputed lightweight champ George Kambosos.
Fury and Usyk took a friendly picture with Arum.
Many boxing fans noticed the difference in size between the Heavyweights. Some believed Fury would 'overwhelm the Ukrainian'.
Boxing isn’t afraid of David v Golaith stories.
Famously, David Haye beat Nikolai Valuev, a Russian giant, to win the WBA heavyweight title back in 2009.
This is not Fury and Usyk's first conversation in recent weeks.
Fury jokedly joined FaceTime with Usyk, and said 'I'm coming' to him.
Sugarhill Steward, Fury's coach, said that Tyson is simply Tyson. He loves everything and the excitement.