Jackie Evancho Is Big Hit on 'Britain's Got Talent'

After wowing American audiences for nearly a year, Jackie Evancho crossed the pond to perform in London this weekend and blew away an audience at the finale for "Britain's Got Talent."

Evancho was the runner-up last summer in the British show's American cousin -- NBC's "America's Got Talent." It catapulted her to international fame as she amazed the judges and audiences with her soaring adult-like voice.

British hosts Ant and Dec introduced her Saturday night with video clips from home and past performances, calling her "an ordinary schoolgirl who blew America away when she entered its biggest talent contest." 

Encircled by hundreds of candles on the stage floor, the 11-year-old Evancho sang "Nessun Dorma" from Giacomo Puccini's opera "Turandot" in her live United Kingdom debut performance.

Click here to see the YouTube video of her performance.

The audience broke into applause as soon as she started to sing and then clapped sporadically throughout the performance.

A huge smile covered Evancho's face when the song ended.

TV cameras showed the four judges -- media mogul Simon Cowell, actor/singer David Hasselhoff, actress Amanda Holden and comedian Michael McIntyre  -- giving her a standing ovation.

"Wow, that was incredible! Incredible!" host Dec exclaimed. "Jackie, thank you so much for coming to see us tonight."

"Thank you for having me," the ever-polite Evancho said.

"You're used to nights like this, aren't you. You were in the final of 'America's Got Talent' last series. Try and sum up for us, if you can, how nervous will our acts be feeling right now?" the host asked.

"I really think that these acts -- that are amazing -- are probably feeling really really really scared, and um, my advice for them is that they should just be relaxed and just have confidence in yourself and let yourself know that you're going to do great," said Evancho.

"Is that what you did?

"Yup. That's what I did," she said with a big smile and loud applause from the audience.

"Appearing on 'America's Got Talent' really did change your life, didn't it?" said Ant.

"It did. It changed my life  a lot," she said with a giggle.

Ant continued: "Now you're flying all over the world, performing for everybody. ... Brilliant."

Dec: "The only down side is that you have to stand in front of Simon Cowell."

Jackie giggled and said, "I think that's a great honor."

Cowell signed Evancho to a contract with his music company, SYCO.

In an interview published by MailOnline.com in Great Britain, Jackie is quoted as saying -- with a giggle -- that she would like to sing "at Simon Cowell’s wedding."