I said in yesterday's Weekend TV preview that the moment Susan Boyle walked onto stage for her Britain's Got Talent audition, opened her mouth and blew away a nation's preconceptions was one of those magical television moments that it's impossible for the show to replicate, only one day match if it's lucky.

Well, 24 hours later, and it seems that day may have arrived - in the form of Jonathan Antoine, a shy 17-year-old who has suffered years of bullying in the school yard on account of his weight. At his side was Charlotte, his loyal friend who has made it her business to defend him whenever she can.

It was Charlotte who told the panel of Simon Cowell, Alesha Dixon, Amanda Holden and David Walliams how their singing teacher had suggested they come on the show. Jonathan seemed too shy to speak, and Cowell had one of those let's-just-get-through-this-quickly faces on - head down, chin on hand. He was even spotted whispering to Dixon, "just when you thought it couldn't get any worse"...

And then Jonathan and Charlotte started to sing.

The Prayer (originally a hit for Charlotte Church, Josh Groban, Andrea Bocelli, Celine Dion and others) is nominally a duet, but let's make no mistake, it was Jonathan who captured the audience's imagination, belting out the song and becoming increasingly confident and powerful, with an operatically-trained tenor voice of richness and maturity that belied his teenage years.

It brought Cowell and Co to their feet. But it also brought a dilemma, as it was clear that Jonathan was a far more striking performer than Charlotte, something Cowell wasted no time in pointing out, telling Jonathan - "in my head, I'd say you should dump her."

Jonathan was having none of it, paying back the years of support at the school gate, standing his ground and saying "We started as a duo, we'll stay a duo." Which only brought more applause.

The judges unanimously voted 'the duo' through to the next round, which raises the thorny issue of how far 'the duo' can progress, or whether the producers will find some way of accommodating Charlotte's standard pop voice alongside Jonathan's astonishing sound.

Charlotte herself seems aware of this. When asked afterwards if this was a life-changing moment for them, Jonathan smiled and said "yes", while she looked at him with a sad smile and said, "yes, I think for you..."