The 'Titanic' star was drinking with club promoter Danny A and a group of pals on Sunday night at swanky venue Upstairs when a fellow partygoer started shouting at Danny.

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"Danny was getting into an altercation by the bar with a regular patron. Leo jumped up from his seat and stood right behind Danny. He was just glaring at this guy over Danny's shoulder, with his posse behind him." an onlooker said.

The reveller immediately backed down, allowing Leonardo and Danny to continue partying in peace.

Danny has played down the incident, saying: "I have security. I don't use my friends."

Meanwhile, the 'Blood Diamond' star had reportedly spoken to the 81-year-old adult magazine editor about making a biopic based on his extraordinary life as it was recently revealed Leonardo wanted to play Hugh Hefner in a movie about the Playboy icon's life.