Voice contestant Colin Chisholm snapped the unwitting presenter making the gesture before posting it onto his Facebook page.
The 60-year-old had a brief brush with fame in the 1970s with Scots rock band Bilbo Baggins but has been given a second chance after being selected by Tom Jones on Saturday night’s show.
He posted on Facebook: “Thanks everyone! That was amazing! Here’s my pal Holly Willoughby helping me celebrate 51 years in the music business...Or something like that :-)”
Hearts fans have roped a number of celebrities, including David Hasselhoff and Suggs, into making the 5-1 gesture.