Former Iron Maiden singer Paul Di'Anno stopped the show during a concert in Donetsk, Ukraine, after a member of the audience kept shouting Bruce Dickinson's name. Scroll down to watch video of the incident.
The singer referred to his successor's celebrated "air raid siren" voice and made a homophobic reference to him.
Di'Anno said: "I'm sorry I don't do opera," and mimicked Dickinson's vocal on 'Run To The Hills'. He added: "It's too f--king easy and I'm not gay."
"This is punk. If you like Bruce Dickinson go home and listen to his records. Why did you buy a ticket, motherf--ker? This is real punk, man. This is what made Iron Maiden not the money-making machine.
"If you don't like me, f--k off. Better still you want to fight? You'll be sorry. I'm sorry, I didn't say I was a nice guy. You f--k me up, I'll kick your f--king ass."
He then delivered a rendition of early Maiden track Running Free, describing it as "the song that made Iron Maiden famous," and adding: "It's about sex, drugs, rock'n'roll, Harley Davidson motorcycles."
Di'Anno, who recently spent time in jail after being found guilty of benefit fraud, fronted the NWOBHM giants for their first two albums before being replaced by Dickinson in 1981.