What's the smallest league you've won the Champions League (or Europa league) in?

I once won the UEFA cup with Leeds whilst not in the Premier League (had won the FA cup the season before in league one). Never won with a club from outside the big leagues though, as I dont tend to play outside Spain, England, Germany, France or Italy.

Never had a perfect season either. Also, to be a PERFECT perfect season, you shouldnt concede a single goal - try that for an impossible challenge!