Gabby Agbonlahor came off the bench to score the winning goal for Aston Villa as Harry Redknapp's first game as Birmingham boss ended in a 1-0 derby defeat.
Agbonlahor's introduction as a substitute just before the hour at Villa Park immediately brought an otherwise dour encounter to life.
Making his return from a three-month layoff with a hamstring injury, the 30-year-old was immediately in the thick of the action, getting involved in a scuffle with Ryan Shotton before being booked.
He made the telling contribution in the 68th minute, nine minutes after entering the action, when he turned the ball home for his first goal since February 2016.
It was not the start Redknapp had hoped for after agreeing this week to oversee Birmingham's remaining three Championship matches following the departure of Gianfranco Zola.
The Blues remain one place and two points above the relegation zone and Redknapp now has games against Huddersfield and Bristol City in which to fulfil his remit of keeping the club in the division.
The afternoon began with Villa and Birmingham fans uniting to observe a minute's applause in tribute to Ugo Ehiogu, the former Villa defender who died this week aged 44 following a cardiac arrest.
There was little love lost when the action began, with a robust tackle from Mile Jedinak on Maikel Kieftenbeld bringing the crowd to their feet.
But that was all there was to get excited about until late in the first half. The game's first real chance arrived in the 38th minute when Lukas Jutkiewicz crossed for Che Adams but, with the goal at his mercy, the Birmingham forward steered his shot over the crossbar from 10 yards.
Villa responded before the break as Leandro Bacuna flashed a shot across the face of goal.
It was similar fare in the second half as both teams continued to lack fluency, and a fine fingertip save from Villa's Sam Johnstone to deny David Davis proved pivotal moments before Agbonlahor struck.
It was a scrappy goal, much like the game, but the striker was in the right place at the right time to fire the ball into the roof of the net following some head tennis in the Birmingham penalty area.
Redknapp's side tried to engineer a chance to equalise, but the closest they came was three minutes from time when Davis flicked a header just wide.