"We showed great character and team spirit and in the end I thought we were worthy winners.
The manager also paid tribute to the travelling City fans, who witnessed their side move into third place in Group H of the competition.
"The fans were magnificent tonight and we're pleased to have given them something to celebrate," he added.
"We knew before we even got here that our supporters would be immense - they always are - and they certainly didn't let us down."
Birmingham continue their Championship campaign on Sunday with a trip to Nottingham Forest.