Birmingham's win was certainly well merited and they set out their game plan very early in the match when they imposed themselves on the opposition which struggled to find their top form.
After picking up only one point from their first three games Birmingham are rapidly coming to terms with life in the Premiership and this was their best performance since gaining promotion.
Striker Clinton Morrison, watched by Republic of Ireland manager Mick McCarthy, made an impressive home debut and gave Dominic Matteo a torrid time.
Ian Harte was also ill at ease against the pace of Devlin as Birmingham hit Leeds with a series of positive attacks in which Robbie Savage and Aliou Cisse were the two players driving from midfield.
Manager Steve Bruce had every reason to be pleased with the confidence and standard of his team against a Leeds side which struggled to make an impact following their midweek defeat at the hands of Sunderland.
Birmingham finally gained their reward in the 32nd minute when Devlin scored with a low shot following a swiftly taken corner on the right which completely deceived the Leeds defence.
The response from Leeds was a couple of yellow cards picked up by Eirik Bakke and Bowyer for reckless tackles.
Leeds, however, lifted their game as an attacking unit with Mark Viduka and Harry Kewell both hitting the woodwork just before half time.
Five minutes into the second half Birmingham's defence was hood-winked by a back-heeled pass by Viduka to Bowyer who slipped home an easy equaliser from a few yards.
But Birmingham bounced back to grab their second goal when Damien Johnson collected a low pass form Stern John to score with a high curling shot into the far top corner of the net