Published Friday, 09 November 2012
The Maggie May hitmaker was caught on camera breaking down in tears as he saw Scottish side Celtic beat Spain's FC Barcelona 2-1 in a European Champions League game in Glasgow on Wednesday.
Stewart was shown footage of the incident during an appearance on Graham Norton's UK talk show the following day, and confessed he was embarrassed by the emotional moment.
He told the audience: "Barcelona is supposed to be the best team in the world and they are brilliant.
"If you like football they are the best team to watch and they have such a huge bank account they can buy any player they want. Celtic, on the other hand, have a minimal bank account. So, to take them on and actually beat them is just wonderful... (I'm a) silly old sod."
The interview with Stewart airs in the UK on Friday.