A late strike from substitute Lewis McGugan saw Town slip to a narrow defeat to Nottingham Forest, after being reduced to nine men by referee David Webb.
Lee Martin was dismissed in the first-half for an alleged elbow on Henri Lansbury, before Richard Stearman was shown a second yellow card after the break with the scores still goalless.
Despite battling bravely, Blues eventually came unstuck in the 84th minute, as McGugan’s long range effort deflected beyond Stephen Henderson.
Mick McCarthy was forced into making two changes to the side that beat Leicester last time out, with Andy Drury replacing the injured Carlos Edwards and Daryl Murphy starting in place of the ineligible David McGoldrick.
Luke Chambers, who left the City Ground for Portman Road in the summer, skippered the Blues against his former club.
With the mist rolling in from the Trent, conditions were difficult for both sides as a thick fog set in over the City Ground pitch.
However it was Blues who fashioned the first real opening, with Drury finding Martin in space some 25 yard from goal and the midfielder was unlucky to see his dipping drive fly just over Karl Darlow’s crossbar.
The hosts responded strongly though and a superb solo run from Lansbury saw him skip past three Town challenges before the former Arsenal man was denied by a smart save from ‘keeper Henderson.
Shortly after though the half’s main talking point arrived. Martin jinked past the challenges of Lansbury and Gonzalo Jara and appeared to be tripped in the area, although referee David Webb only awarded a free-kick on the edge of the box.
Drury quickly played the ball square to Murphy who slotted home, but the man in the middle again angered Town by disallowing the goal to pulled the game back and insisted Blues waited for him to blow his whistle.
But Mick McCarthy’s side were edging proceedings and another incisive break from Blues saw Chopra force Darlow into a smart save with his legs, with Guirane N’Daw having his follow up effort deflect wide for a corner.
However despite being on top, things were soon to take a dramatic twist for Town after Martin was shown a straight red card for an apparent elbow on Lansbury.
The former Manchester United man was fouled by the Forest midfielder on the edge of the area but as the pair got to their feet, Martin flicked out an elbow to the face of Lansbury and the referee showed him his marching orders.
On the stroke of half-time, Billy Davies’ men almost broke the deadlock, but Simon Cox’s effort looped onto the roof of the net before time was called on an entertaining first 45 minutes.
Forest started the second-half as they ended the first, with Cox going close for the hosts but the striker could only drag his shot wide after cutting inside the challenge of Stearman.
However the odds were further stacked against Town in the 68th minute as the referee produced another red card, this time against Stearman.
The Wolves loanee, who had been booked for a strong challenge on Cox in the first-half, was shown a second yellow card midway through the second-half after a tangle with Andy Reid by the touchline.
Despite their numerical advantage, Forest were struggling to break Town down and efforts from Reid, who curled just wide, and McGugan who shot straight at Henderson, did little to change that.
However it was always going to be a big ask for the nine men of Town to hold out and Forest broke the deadlock with six minutes remaining.
McGugan’s speculative shot from range took a wicked deflection, which wrong-footed Henderson and the ball nestled into the bottom corner for the first goal of the evening.
Blues did throw everything at it and a smart run and cross from Elliott Hewitt almost saw the ball break for Frank Nouble, but the big striker couldn’t get a shot away.
Forest almost sealed the win in injury time, but Cox fired wide of the target after being sent through by strike partner Dexter Blackstock.
That was the way it finished as Town were defeated by the Reds despite showing a battling display with just nine men.