Campbell reached the final alongside fellow singer Bernie Nolan. The pair performed in front of the previously evicted contestants as well as a live audience in the race for first place.
Following their songs, the two lined up for the result as host Myleene Klass prepared to reveal the public vote. In the pause prior to the announcement, several audience members called out for Nolan to win.
However, Campbell was named victorious, looking shocked at the news as Nolan congratulated him.
After the result, Nolan seemed unfazed by her defeat, saying: "Thanks everyone... it's been amazing."
Campbell then closed the show with a final rendition of 'Non Piu Andrai'.