Ten-man Town lost to a last minute goal for the third successive away game as Derby came from behind to win 2-1 at Pride Park. Gary Roberts put the Blues ahead with a stunning strike but goals from Steve Howard and Arturo Lupoli won the points, Simon Walton having been sent off just before the hour.
As expected, Richard Naylor came into the side for Matthew Bates - who returned to Middlesbrough after suffering his injury at Barnsley - with Alex Bruce moving to right-back. Owen Garvan made his first start of the season in place of the suspended Sylvain Legwinski in midfield.
Up front, Billy Clarke recovered from his ankle problem and took over from Jon Macken alongside Alan Lee. Keeper Lewis Price was making his 50th appearance for the Blues.
Derby frontman Jon Stead hit the first shot of the game but sent the ball wide of the post. The Rams came close to opening the scoring in the eighth minute when Michael Johnson diverted Seth Johnson's deflected freekick over the bar.
The Blues' first chance of the game came in the 14th minute, Billy Clarke nodding Matt Richards's freekick wide at the far post.
Stead beat Bruce down the Derby left rather too easily in the 29th minute, but Price saved his shot.
On 38 Derby had the ball in the net, but Steve Howard pushed Jason De Vos as Paul Boertien's cross came in from the left and referee Ray Lee awarded Town a freekick.
A minute later the Blues went in front. A half-cleared Alan Lee cross dropped to Gary Roberts on the edge of the area, the loanee from Accrington Stanley timing his strike perfectly and giving Derby keeper Stephen Bywater no chance. It was Roberts's first goal for Town and his ninth of the season.
Derby looked to get back on terms immediately, but David Jones eventually put a 25-yard freekick over the bar after protracted negotiations with the referee over the placing of the ball.
Just before the break, Simon Walton was booked for a foul, referee Lee having already appeared to have warned him about an earlier challenge.
The Rams will have felt hard done by to go in behind at half-time, but the Blues had enjoyed a good spell of football in the middle of the half and Roberts's goal was almost worth the exorbitant £27 ticket in the away end on its own.
Three minutes into the second half Owen Garvan picked up his second yellow card of the season for a foul on Morten Bisgaard.
It was the Town fans making all the noise as the half started, but on the pitch the home side put on the pressure, Stead diverting a Giles Barnes cross from the left wide.
On 53 the Rams equalised. Bisgaard sent in a corner from the left and Steve Howard headed into the corner of the net, with Jason De Vos complaining that the former Luton man had once again shoved him aside as the ball came into the box.
Straight from the Town kick-off Owen Garvan was the victim of a late tackle from behind by Seth Johnson which saw the one-time England man get his name in referee Lee's book. The Irish youngster required lengthy treatment before returning to the fray.
In the 58th minute Town were reduced to 10 men. Simon Walton needlessly threw himself into a wild lunge well inside the Derby half, sending Michael Johnson crashing to the ground. Referee Lee had no alternative but to issue a yellow and then a red card to the loanee from Charlton, who now misses Saturday's home game with Burnley.
Town reorganised with Billy Clarke going to the left of midfield and Matt Richards into the middle.
The home side set about getting a second goal but found Lewis Price on stubborn form, the Wales international brilliantly getting down to his left to stop Arturo Lupoli's volley one-handed.
Gavin Williams replaced Billy Clarke and went to centre midfield, Richards returning to the right flank, prior to Alan Lee receiving his fifth yellow card of the season for a challenge on Marc Edworthy.
The former Norwich man made an awful lot of little contact, as was also the case with several of his colleagues, and the Town striker mocked the Derby defender with an invisible violin as he limped off, only to miraculously return fully fit moments later. Lee now misses the trip to Cardiff City.
Stead sent the ball across the Town box from the right, but no one was there to add a touch. Soon after, Michael Johnson got his name in the referee's book for a tackle from behind on Alan Lee, the pair having enjoyed a lively battle throughout, the referee's decisions usually going in favour of the Derby man. The resultant freekick eventually fell to Gary Roberts on the edge of the area but his shot was straight at the keeper.
Lupoli shot across the face of Price's goal, before Sito took over from Roberts, the Spaniard taking up a right midfield role. Despite Derby having the vast majority of the possession, Town were defending well with Lewis Price rarely seriously tested, while the home crowd were becoming increasingly frustrated at their side's failure to break down the Blues' defence.
Michael Johnson was very lucky to remain on the field in the 83rd minute after tackling Lee from behind just outside the area. The Derby skipper, already yellow-carded, appeared to compound his transgression by complaining strongly to the referee, but surprisingly Mr Lee chose to keep his cards in his pocket. Garvan put the freekick wide.
David Jones added his name to the lengthening list of cautioned players in the 87th minute after pulling Gavin Williams back on a rare Town break.
Town's backs to the wall display after Walton's red card was worthy of a point, but as at Burnley and Barnsley there was a late sting in the tail. Once again the Blues failed to defend a set piece, Michael Johnson heading Bisgaard's corner on to Lupoli, who, unmarked, nodded into the net.
Once again Town's defensive failings at set pieces cost points and the last minute goal gifted to the opposition is becoming all too predictable. The determined defensive display after Simon Walton's daft red card was worthy of a point but organisation and concentration were again lacking as a match entered its final moments.
Town: Price, Bruce, Harding, Naylor, De Vos, Walton, Garvan, Richards, Roberts (Sito 76), Lee, Clarke (Williams 62). Unused: Supple, Haynes, Macken. Att: 22,606.