Trained by schoolgirl Ashleigh Butler, the mutt raved along to the theme tune to The Flinstones, delighting the Cardiff auditorium.
Butler, 16, reveals backstage: "Me and Pudsey have an amazing bond, I walk him, feed him, groom him… I do everything with him.
"I've come on Britain's Got Talent because I know Simon has been looking for a new Lassie for quite a while, and I hope Pudsey can fill those boots."
Simon Cowell, after smiling throughout the performance, reacts: "You know me, I love a dancing dog. Pudsey, you're one of the best dancing dogs I've ever seen."
Alesha Dixon comments: "I've been dying to see a dancing dog. That was fantastic."
Cowell has consistently stated his determination to find a winning dog act, having come close with Gin in series two, Tippy Toes in series three and Chandi in 2010.
Britain's Got Talent airs at 8pm on ITV1, with Britain's Got More Talent following afterwards at 9.15pm.
> Stephen Mulhern's Britain's Got Talent blog: Week Three
Watch a teaser video of Pudsey's Britain's Got Talent audition below: