Roberto di Matteo made a positive start to his Chelsea reign as goals from Juan Mata and Raul Meireles sealed their passage into the FA Cup quarter finals.
It was a disappointing night for Birmingham City, who could not muster the level of performance needed for what would have been an impressive scalp.
The diminutive Spaniard was wasteful in a dull first half and missed one-on-one to put the Blues ahead early.
The home side nearly punished them for this mistake but Nikola Zigic’s header was not quite good enough to beat Petr Cech
An initially noisy St Andrew’s was quietened but an extremely dull first half and they could not have been expecting much more for the second half.
Mata was the danger again and after 54 minutes he opened the scoring to relieve the tense travelling Chelsea fans.
It wasn’t the attractive kind of goal that normally associate with the young playmaker, but he won’t care as he was on hand to scramble home after Birmingham failed to clear Ramires’ cross.
The game was effectively put to bed five minutes later when a Branislav Ivanovic crossed was laid off by Ramires to Raul Meireles, who finished emphatically into the roof of the net.
It sealed a satisfactory win for Di Matteo who also saw a Mata penalty saved after Fernando Torres was brought down.
The Stamford Bridge side will happy with what was a comfortable, if unimpressive, win over the Championship side.
Di Matteo will surely expect greater challenges in the next few weeks, but he can be nothing except satisfied after a tie that had the potential to become a banana skin.