The Brewers move five points clear of the Championship relegation zone as a result of their fourth victory since promotion to this level, while their opponents missed out on the chance to move up to third.
It was City who headed into the fixture as favourites, aiming to maintain a run of just one defeat in their last nine outings, but they came unstuck to a goal in either half on Gary Rowett's return to his former club.
Birmingham started the brighter, too, getting in behind their opponents on a couple of occasions but being denied by some last-ditch defending at the back.
Jamie Ward squandered a good chance to blast Albion ahead 20 minutes in after being picked out by Lloyd Dyer, but it was roles reversed soon after as the former turned provider to set the winger up for Burton's opener.
Burton did have a second on the hour when Ward got on the end of a long ball and finished past Legzdins, putting his side well on course for just a second win in their last eight.
Michael Morrison headed wide unmarked from close range in City's best chance to pull one back, but in the end it was the two Birmingham-born players who made the telling difference on the night.