Alex McLeish admits he was taken by surprise by the intensity of the Aston Villa-Birmingham derby and compares the rivalry with the Old Firm tussles in Glasgow.
But the Blues boss has warned of the need for his Blues players to "control their emotions" in Sunday's noon showdown at Villa Park.
McLeish admits himself and his players "reacted badly" after Villa triumphed via a controversial penalty in the corresponding fixture last season.
Central defender Roger Johnson, who was alleged to have brought down Gabriel Agbonlahor, was fined by the Football Association after criticising referee Martin Atkinson, while full-back Stephen Carr was handed a one-match ban for gestures towards Villa fans.
McLeish admitted ahead of Sunday's Barclays Premier League clash: "The derby compares absolutely favourably to the Rangers-Celtic derbies.
"I underestimated it in the beginning and the fans really love each other down here don't they?
"It's a little bit similar to Glasgow. In Glasgow it divides the whole city. The Birmingham derby is quite tasty as well.
"It's very much a derby that is up there with the best of them."