Sister Cristina, a 25-year-old nun from Sicily, southern Italy, was performing on the Italian musical talent show “The Voice” during a blind audition on Wednesday night where the show's judges have their back turned to the stage for part of the song.
When the judges are finally allowed to turn around and see the performer, their shock is evident.
Undaunted, the nun continues her energetic performance, cheered on by three nun supporters backstage.
After the performance judge Raffaella Carrà asks her: “How did you end up on The Voice?”
“I have a gift and I'm giving it to you,” replies the contestant.
“If I had found you at mass I would always be in church,” joked another judge, the Italian rapper known as J-Ax. “You and me are like the devil and holy water.”
When asked what the Vatican would think of her performance on national television the nun replies: “I hope that Pope Francis will call me now.”
Viewers were also wowed by the performance, with some saying it helps to bring the Catholic Church "closer to the people".
Maurizio Rossi only stumbled across the show last night because his son was watching it.
"I thought she was strongest contestant of the lot," he told The Local.
"I liked the song she sang and she sang it very well. It's 2014, why shouldn't a nun take part in such a contest? If she likes to sing and it makes her feel good, then good for her."
Giovanni, who runs a newspaper stand in Rome, told The Local a nun taking part "is not something absurd" and also shows that the Catholic Church isn't so "closed".
"I think it's really nice," he said.
"And it shows an affection and closeness to the people."
Giuseppe Palozzi, who works in a furniture shop in Rome, agreed.
"I don't watch the show but I heard a nun was taking part," he said.
"I think this reflects that the Church is not as rigid as it was before - maybe Pope Francis is helping it to be more open."
Meanwhile, Twitter has been abuzz with the hashtag #suorcristina.
"Sister Cristina I remember so well my religion teacher from middle school, Sister Natalia, who was much less nice!!" tweeted @stefyorlando.
"Does anyone know if @Pontifex_it (the Pope's official Twitter account) has already phoned Sister Cristina?" wondered @PegasoNero.