Sinclair Armstrong’s first half strike proved enough for Bristol City to consolidate their place in the Sky Bet Championship play-off places, sealing a hard-earned 1-0 victory over Birmingham at Ashton Gate.
The decisive moment came in the 42nd minute when the powerful striker raced onto a Rob Atkinson through-ball and outpaced the Birmingham defence before a slotting a cool right-footed finish beyond the reach of goalkeeper James Beadle.
Blues paid for not having a cutting edge, particularly in the second half when they dominated for long periods without seriously testing Robins goalkeeper Radek Vitek, and there was only frustration to show for their considerable efforts.
The hosts gave a start to Armstrong, who impressed as a substitute in the 3-1 midweek home win over Southampton, in place of the injured Emil Riis, and brought in Ross McCrorie for Mark Sykes at right wing-back.
Birmingham also made two changes from their 1-0 win at Preston, with Marc Leonard and Patrick Roberts replacing Lewis Koumas and the suspended Bright Osayi-Samuel.
Blues made a fast start and when the home side lost possession in a dangerous area inside a minute, Roberts sent a low shot narrowly wide from the edge of the box.
A closely-fought first half developed with both defences coping well with some threatening attacks. Beadle saved a 12th minute cross-shot from Neto Borges and Rob Dickie headed wide from an Anis Mehmeti free-kick, while at the other end Zak Vyner produced a timely block from a Jay Stansfield shot.
Armstrong’s goal came as something of a surprise and Birmingham could feel a shade unlucky to be behind at half-time.
Tommy Doyle fired over from distance for Blues at the start of the second half before Scott Twine volleyed wide at the other end when in space inside the box.
It remained a close contest as Paik Seung-Ho headed wide, to the dismay of the massed ranks of Birmingham fans behind the goal.
Blues boss Chris Davies made a triple substitution just past the hour mark, sending on Koumas, Demarai Gray and Kyogo Furuhashi for Roberts, Keshi Anderson and Stansfield.
The visitors then enjoyed a spell of pressure, which saw Leonard send a curling shot just over. Gray volleyed inches too high from a Koumas cross moments before the Robins replaced the impressive Armstrong with Fally Mayulu.
The home side had faded entirely as an attacking force and were forced to work tirelessly to repel incessant Birmingham attacks.
Substitute Sykes came to their rescue with a last-ditch clearance from a dangerous right wing cross and six minutes of stoppage time tested the nerves of home fans, but their hugely committed team held out.
