The Naked Jungle presenter, better known as 'Cheggers', told the Daily Star Sunday that they were children at stage school when the Genesis singer penned the tune.
The 54-year-old revealed: "I was in a school play and I was singing the first song that Phil Collins ever wrote. Yeah, true story.
"I went to the Barbara Speake Stage School and his mother ran the school. Phil was there too and he wrote a song and I sang it.
"So the first character or part that I had in the show was singing a Phil Collins number, the first song that he ever wrote and I've still got a copy of it!"
Chegwin returns to UK TV screens later this year in Ricky Gervais's Life's Too Short, in which he makes a cameo alongside the sitcom's star Warwick Davis.
> Video: Keith Chegwin gets killed in new horror movie
Watch Warwick Davis talk about 'Cheggers' with Digital Spy below: