Wolves 0 Birmingham 1
Wolves' survival hopes took another dip as they suffered their third straight defeat and lost winger Michael Kightly to injury.
Blues made it five games unbeaten – their best run in the Premier League under Alex McLeish - to inflict Wolves' eighth game without a win.
Kightly, on as early as the 32nd minute for Greg Halford, suffered what looked like an injury to his left ankle after trying to get around Liam Ridgewell on the touchline.
The much-missed wide man tried to battle on, but was clearly struggling and came off in the 66th minute.
Blues took the lead with the first attack of the game with just 125 seconds on the clock. It was a cracking effort too, Lee Bowyer chipping into the roof of the net from the edge of the area after Sebastian Larsson cut the ball back from the right.
The visitors continued to dominate and could have been three or four goals to the good by the break as Wolves, perhaps sensing the gravity of their situation after going into the game four points from safety, looked more tense and nervous than in any match this season.
Although Dave Edwards sent a free header wide from a Matt Jarvis cross in the best chance of the game along with Sylvan Ebanks-Blake's late headed chance, Blues forced goalkeeper Marcus Hahnemann into four first-half saves in his first Premier League game for Wolves.
Hahnemann was preferred to Wayne Hennessey, who was taking out of the firing line, in one of three changes made by boss Mick McCarthy.
But it made little difference as Blues were good value for their lead. Bowyer's low drive, Larsson's angled volley and Cameron Jerome's shot all forced the American into falling saves.
The USA international's best work was a superb tip-over, from a Bowyer shot that deflected off Kightly. The winger had replaced Halford, who was sadly below par apart from his long throws.
Wolves lacked any spark or creativity and just couldn't keep the ball at all in one of their most ineffective displays for some time.
And this was the last game they needed to have an off-day, coming against one of their rivals in the battle for survival.
McCarthy's men improved slightly after the break and Kevin Doyle almost gave them a lifeline with a left foot drive that flew inches wide within 30 seconds of the restart.
But Blues never allowed Wolves time to settle and the visitors rarely looked in trouble.
Wolves should have done better with two late chances, when Jarvis's volley was denied by a flying save from Joe Hart, and when Ebanks-Blake in his 150th senior game could only guide a free header wide from Dave Edwards's cross.
Christophe Berra then headed over from Nenad Milijas's free kick deep into time added on.
The only bright spot for Wolves was the return of Stephen Ward – one of three left-backs used on the day by McCarthy - from the bench in his first senior game since August 22.
