The TV duo celebrate over 20 years as a partnership on the chat show, which sees Alan Carr acting as a vicar.
Rylan Clark also appears as the pair's pallbearer, while the audience serenades them with one of their biggest hits 'Let's Get Ready to Rhumble'.
Ant McPartlin said: "We've lasted because we are friends."
He added that he made the "first move" in their friendship while playing PJ & Duncan on Byker Grove.
"I remember sending him a Flintstones Christmas card saying, 'Have a yabba dabba doo Christmas. Do you fancy coming to the Newcastle v Grimsby game on Boxing Day?'."
Following their Byker Grove acting days and musical career, the duo moved into TV presenting, leading to stints as hosts of Saturday Night Takeaway, Britain's Got Talent and I'm a Celebrity, among many other shows.
They recently revealed that they experimented with drugs in the early stage of their career.
Alan Carr's Chatty Man airs tonight (March 8) at 10pm on Channel 4.
Watch the video for 'Let's Get Ready to Rhumble' by Ant & Dec (as PJ and Duncan) below:
Ant & Dec's career - in pictures: