Town find themselves 1-0 behind to David Edgar’s goal scored on the half hour mark at Birmingham City at half-time.
Boss Mick McCarthy handed new loan signing Conor Sammon his full debut and Paul Anderson his first start of the season with David McGoldrick and Elliott Hewitt dropping to the bench.
The game got off to a quiet start, skipper Luke Chambers weakly hitting the first shot through to home keeper Darren Randolph from distance in the sixth minute.
Town, in orange, had had the better of the opening spell and seriously threatened for the first time in the 10th minute. Anderson’s cross from the left found Jay Tabb, whose shot deflected to Daryl Murphy, but keeper Randolph saved the Irishman’s 10-yard effort.
Anderson, who had temporarily switched flanks with Tabb, got away down the left again in the 13th minute but Sammon was unable to do anything with his cross and the ball ran back out wide. However, the Blues midfielder's subsequent strike flew a long way past the post.
There was a scare for the Blues in the 15th minute when Dean Gerken dropped the ball from a Jonathan Grounds freekick from halfway. The keeper felt he had been fouled but Lee Novak in any case sent the loose ball well over. Two minutes later, the former Huddersfield man headed Paul Caddis’s right-wing cross straight at Gerken.
The Blues then had a couple of opportunities to break the deadlock at the other end. Tabb, who was back on the left, brought the ball inside and fed Luke Hyam but the midfielder scuffed his shot. The loose ball fell to Murphy but the striker’s mis-hit effort looped well wide.
Novak shot wide for the home side in the 23rd minute, then at the other end Chambers beat Clayton Donaldson in a challenge midway inside the Birmingham half but then scraped a poor effort well wide.
Birmingham weren’t too far away from going in front on 25 when David Cotterill found himself space on the right and crossed low towards Donaldson, but the former Crewe man diverted the ball wide from six yards.
On 29 Cotterill sent over another dangerous right-wing cross which Wes Thomas flicked on to Novak at the far post, but Gerken blocked, the ball going out of play off the Birmingham man.
The home team were looking increasingly threatening and right on the half hour they went in front. Cotterill sent over a corner from the right and an unmarked Edgar powered a header home.
Birmingham celebrated as skipper Chambers, Tommy Smith and Christophe Berra began an inquest into who ought to have been looking after the former Burnley man.
After an Anderson freekick on the right had come to nothing, Novak hit a powerful strike wide for the home team, who ended an 18-game home winless run by beating Brighton 1-0 at the weekend.
Murphy did well to find the space to cross from the right in the 37th minute but Sammon was unable to get to the ball and goalscorer Edgar cleared.
Town couldn’t complain too much about the scoreline at the break. After a subdued start the Blues had got on top and created one or two chances but had failed to take them.
As was the case in the first half at Reading, the home side gradually gained the ascendency and the goal - as on Saturday a very preventable one - had looked increasingly likely when it came. In the remaining quarter of an hour, the Blues, lackong the spark usually provided by the on-the-bench McGoldrick, never seriously looked like getting back on terms.
Town: Gerken, Chambers (c), Berra, Smith, Mings, Skuse, Hyam, Tabb, Anderson, Murphy, Sammon. Subs: Bialkowski, Parr, Hewitt, Bru, Henshall, Bajner, McGoldrick.
Birmingham: Randolph, Grounds, Edgar, Donaldson, Thomas, Cotterill, Novak, Hall, Spector, Davis, Caddis. Subs: Doyle, Robinson, Duffy, Gleeson, Johnstone, Brown, Gray. Referee: Roger East (Wiltshire).