The 49-year-old wooed the audience with an impression of Prince Charles before launching into his self-written 'Lost My Keys, Lost My Phone'.
Zipparah Tafari said to the panel: "It's going to be massive. It's not a case of if but when it will be number one. You can't keep Mr Zip in the house. Mr Zip is global."
Bounding around the stage, he shook each judge by the hand during his song before playfully slapping Ant McPartlin as it reached its conclusion.
Simon Cowell, who had been originally sceptical, admitted: "When you started I thought you were annoying, then you got more annoying, and then I liked you."
Alesha Dixon added: "You have been the highlight of my day so far," while Amanda Holden predicted the rap will reach number one in the UK singles chart.
Britain's Got Talent airs at 8pm on ITV1, with Britain's Got More Talent following afterwards at 9.15pm.
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