Sunderland's late show sent the Black Cats through in the Capital One Cup - and leave Birmingham fuming.
Jordi Gomez, Adam Johnson and Connor Wickham struck in the final 13 minutes to stun the hosts and give the Premier League side a 3-0 win.
But Blues were angered after Gomez's opener, claiming the ball had gone out in the build-up.
The Black Cats made hard work of the win as David Cotterill hit the post and Clayton Donaldson missed for the hosts.
It was harsh on Birmingham, who had matched th...