Blues returned to winning ways and claimed their first three points in six matches in a 2-0 win over Reading at the Madejski Stadium.
Gary Rowett's side put in a perfect away performance. Disciplined in defence and clinical on the counter, as first-half goals from Clayton Donaldson and Ryan Shotton sealed the win.
Rowett made four changes to the side that were defeated by Brighton in midweek.
Adam Legzdins came in for his league debut in place of Tomasz Kuszczak, along with Shotton, David Davis and David Cotterill for Jonathan Spector, Jon Toral and Jacques Maghoma respectively.
Changes that certainly paid off in the opening 45 minutes.
On a rather wet afternoon in Berkshire, it was who Blues started on the front foot and within two minutes were ahead.
Cotterill delivering a superb cross from the right, perfect for Donaldson to attack and head past Ali Al-Habsi for his eighth goal of the season.
The hosts' first chance of note came after eight minutes. Oliver Norwood's corner from the right and a midjudged clearance from Jonathan Grounds, presented the ball to Lucas Piazon six-yards out, but the Brazilian scooped his effort over the top of Legzdins' cross-bar.
Blues allowed Reading much of the ball, whilst the hosts never really threatened Legzdins' goal, then, just before the half-hour mark, Rowett's side doubled their advantage.
Wales international Cotterill again involved, his low struck free-kick from 35-yards parried into the path of Shotton, who slotted home.
As they did following the first goal, Blues allowed Reading to enjoy much of the possession, but again without really troubling Legzdins.
Paul McShane thought he'd pulled one back after Legzdins' fumble looked to have crossed the line, fortunately for the 'keeper the linesman's flag was raised.
As the half neared the 45 minute mark, Stephen Quinn saw his header from 12-yards sail wide of the post and that was as close as the hosts came in a first half where Blues frustrated Reading and did what they do best on the counter.
Reading came out on the front foot in the opening minutes of the second-half.
Quinn saw a volley from the edge of the area clear the bar and Simon Cox nearly profitted from a mix-up between Michael Morrison and Shotton, but Grounds was quickly across to snuff out the danger.
Just before the hour and Legzdins was forced into action. Danny Williams striking a powerful effort from distance, which the Blues 'keeper was equal to and able to gather at the second attempt.
Reading continued to dominate the possession and centre-back Jake Cooper rose highest at a Norwood free-kick but he couldn't keep his header down.
After 70 minutes Rowett replaced Lafferty and Cotterill - the latter instrumental in both his side's goals - with Viv Solomon-Otabor and Maghoma.
Lafferty's exit saw Donaldson return to his usual position as the loan striker and on a rare occassion Blues mounted an attack in the second-half, the Jamaican international was found by a brilliant pass by Davis down the right-hand touchline but as the striker drifted inside, he was unable to sort his feet out and crowded out before being able to get a shot away.
As the fourth official held up the board for stoppage-time, substitute Garath McCleary got the better of Maghoma and got his cross in where Kermorgant headed goalwards but Legzdins gathered easily.
A very satisfying day at the office for Rowett and his squad, a very disciplined defensive display as the first-half goals proved decisive.