On Thursday night, the judges picked one act from the 35 rejects to give a last chance place in the final to.
In tonight's last live show, Simon revealed that it had been given to The Mend, after the judges whittled the choice down to either them, Four Corners or the Twist & Pulse Dance Company.
Speaking to hosts Ant and Dec tonight, Simon explained: "I wanted The Mend, Amanda The Mend, Alesha wanted The Mend and the one the right [David] wanted the Dalek guy.
"They deserved it, you can tell by the audience reaction tonight that it was the right decision."
David Walliams phoned the boys to reveal the choice yesterday, before they returned to the show to kick off the final tonight.