Blues made it three wins on the spin with a deserved 2-1 victory over QPR at St. Andrew’s.
Gary Rowett’s side were forced to come from behind after Matt Phillips had fired the visitors into an early lead.
But a headed goal from Paul Robinson and a 63rd minute penalty conversion from Paul Caddis sealed all three points for the hosts.
There was just one change to the Blues side that beat Leeds United before the international break, with Jacques Maghoma replacing the injured David Cotterill.
It was a scrappy opening to the game, with Blues just shading it in terms of looking the more threatening side.
The first opportunity of note fell to Demarai Gray when he collected Clayton Donaldson’s knock down and fired in a powerful low drive, which Rangers keeper Robert Green did excellently to save with one hand.
But against the run of play it was the visitors that took the lead after 17 through a fine goal from Phillips.
The Rangers winger collected the ball to the right of Blues area before swivelling and letting fly with a left-footed effort that took a slight deflection before evading Tomasz Kuszczak and nestling in the back of the net at the far post.
But it took Blues just seven minutes to restore parity through a headed effort from Club captain Paul Robinson.
The goal stemmed from a free-kick mid-way inside the Rangers half after Jacques Maghoma had been fouled by James Perch, who was also cautioned for the challenge
Gray stepped up and sent in a pinpoint cross deep into the Rangers box, where Robinson evaded his marker and powered the ball home from eight yards.
Just after the half-hour mark Kuszczak had to be alert to push away Tjarron Chery’s well struck free-kick from 30 yards.
With 42 minutes on the clock Gray tried his luck with a fizzing low shot from right on the edge of the box, but it was just a yard the wrong side of Green’s post.
Half-time: Blues 1 QPR 1
Six minutes after the restart Blues were inches away from taking the lead.
A decisive piece of passing play saw Stephen Gleeson lay the ball off to Paul Caddis on the right. Caddis fired in a low pass across the front of the goal, which after taking a slight deflection just evaded Donaldson's outstretched foot with the net at his mercy.
Blues were beginning to enjoy arguably their best spell of the game and were looking particularly threatening on the break.
Gray went on a surging run before cutting into the area and trying his luck with a curling shot but it was deflected behind for a corner.
Although Blues had the upper hand it wasn’t all one-way traffic and Kuszczak was forced to save Phillips’ shot low down at his near post.
With 63 minutes played Blues were rewarded for their positive play when they were awarded a penalty after Onuoha fouled Donaldson.
Caddis stepped up to take it and although Green guessed the right way, the Scot’s shot hit with such force Green was unable to get a hand to it as it smashed into the back of the goal.
Having gone behind, Rangers boss Chris Ramsey made a double substitution after 72 minutes and the changes appeared to give Rangers more attacking impetus, although the Blues defence and midfield continued to stand firm and see out a thoroughly satisfying win.
They now travel Bolton on Tuesday with the aim of making it 12 points from a possible 12.