Ian McKinney fought off the challenge of 14 other competitive quiz buffs to take top spot in the Channel 4 programme.
The former Edenderry Primary School and Banbridge Academy pupil was the star performer in the episode which aired on Channel 4 on Monday, April 10.
The 36-year-old insurance broker, who moved to England a few years ago, now lives in Birmingham with his partner, Rachel Cooper.
Explaining how he came to find himself on the set of a popular daytime TV quiz show, Ian said: “Our house was flooded in June 2016 and we’d gone online to investigate the possibility of signing up for one of those home makeover TV shows. We applied for a few shows, but we didn’t get on any of them.
“We saw the thing for Fifteen to One and I thought I’d apply for that too for the craic. It was a complete surprise when I got picked to be on it.”
Ian travelled to Glasgow for a day’s filming, and over the course of three hours proved his quiz credentials to his fellow contestants and show host Sandi Toksvig, who he said was “really, really lovely” and “really put everyone at ease”.
Reflecting on his win, a very modest Ian said he’d been “lucky with the questions”. “I won the individual show, but I didn’t get a really big score so I didn’t get through to the grand final,” he explained.
“The two boys that were in the final with me, one was a professional quizzer and the other guy was one of these people that just knows everything, so in all honesty they were better than I was.