Brand lost his cool with a male audience member who repeatedly shouted out the name of his ex-wife Katy Perry at his show in New Jersey, reported Sun Online.
Sick of the interruptions, Russell asked for the house lights to be switched on so he could identify the assailant.
People sitting near the guilty party helped the 36-year-old out by pointing at him, prompting the comedian to launch into a scathing rant.
"I wanna see what this person looks like. Turn the lights on for me because I want to achieve some sort of confirmation. Who's the person who keeps shouting that? Come here, let's see ya. Let's see how your mental illness looks in the daylight. It's you, is it? Oh dear.
"I was hoping that your personality was as a result of physical beauty, then I saw you. I thought this guy's confident probably because he's incredibly pretty, but look at you. You look like someone that's fallen off the outside of a church!
"And what is it that you have rattling inside of your mind? Some bizarre combination of alcohol and idiocy... And yet the confidence to continue shouting!" Brand said.
The former couple married in India in October 2010 but filed for divorce last December.