But instead of watching her act die on stage, the funnywoman got the chance to start a new life when the intruder turned out to be her boyfriend - who popped the question.
The marriage proposal came during the Australian comedian's stand-up routine titled Bec By Popular Demand.
She revealed: "I was doing the show and there's a bit where I ask if anyone's got a back-up plan for if someone tried to mug them, and I do a bit of audience banter.
"This hand at the back went up and I saw this person stand up and I thought, 'Oh my gosh, some weirdo's going to storm the stage.'
"They started walking toward the stage and they said, 'I'd propose.' Then he came on stage and it was him."
"I nodded and cried," she added. "And then he said, 'You have to finish the show now.'
"I performed the last 10 minutes with tears streaming down my face."