Sister Suor Cristina performs during the final of the Italian TV show The Voice of Italy in Milan on Thursday. The 25-year-old nun is already a talent show sensation thanks to her habit-clad performances. Marco Bertorello / Agence France-Presse

A singing nun clinched the final of The Voice of Italy televised talent contest on Friday after winning millions of followers with her lively dance act and soulful renditions of lusty pop classics.

Wearing her black habit and a crucifix around her neck, Suor Cristina punched the air and thanked God for her victory, reciting an "Our Father" prayer to the puzzlement of organizers and audience.

"I want Jesus to come in here!" said the 25-year-old, dressed in the sensible black shoes and ankle-length black skirt she has worn throughout the contest.

"My presence here is not up to me, it's thanks to the man upstairs!" said Cristina after prevailing over a 28-year-old hard rocker with long curly hair who had performed Stairway to Heaven.

Cristina, a reformed rebel who had once sung in a band and now lives with fellow nuns in Milan, won a recording contract with Universal but hinted she might shun a full rock 'n' roll career.

"I will go back to my priorities - prayer, waking up early in the morning, school. ... That's fundamental for me to be able to begin something new later on," the Sicilian native told reporters.

Cristina said she was following Pope Francis' appeals to bring the Catholic Church closer to ordinary people and was not shy about her newfound success.

"I have a gift to give, and I am giving it to you; what can I do about that? Jesus has called upon me. It wouldn't be worth much if I kept it for myself," she said.

She shot to television fame in recent months in this predominantly Catholic country with her versions of songs like Girls Just Want To Have Fun and Time of My Life from the film Dirty Dancing.

It was a performance of Alicia Keys' No One that first drew attention to her in March, and she sang the tune again on Friday to cheers from an audience that included nuns from her Ursuline Order.

There was some confusion when one panel judge - rock star Piero Pelu - joked that she was the "devil incarnate", prompting the host to quickly add that it was meant with "maximum irony".

The talent show was apparently being followed in the Vatican corridors of power, with top culture official Cardinal Gianfranco Ravasi tweeting a quote from a Roman thinker: "If we commit injustice, God will leave us without music".

Suor Cristina had already sung alongside such luminaries as Kylie Minogue and Ricky Martin during the show, and Keys defined as "pure energy" Suor Cristina's performance, which received more than 50 million YouTube hits.

She also received a celebrity endorsement from actress Whoopi Goldberg - star of the 1990s film Sister Act where she is a singer playing a nun.

But Cristina still defined herself as a "humble servant" and ascribed her sudden success to a "thirst for joy, for love, and a message that is beautiful and pure".

"Since Pope Francis talks of a Bible of joy, I think I'm on the right track," she said in the runup to Friday's showdown.