Town suffered the heartbreak of conceding a winning goal in added on time for the third successive away game after Gary Roberts had given Blues the lead with a wonder strike. Simon Walton was also sent-off.
The winger smashed in a brilliant volley from 25 yards to give Town the lead seven minutes before the break before Steve Howard levelled the scores with a header early in the second-half from a corner.
Blues then lost Walton for a second yellow card on the hour but defended manfully against a Derby side boosted by the confidence of a five match winning streak.
It looked enough to earn a point until Arturo Lupoli stooped to head in from a corner in added on time to leave Blues beaten again right at the death, following on from similar defeats at Burnley and Barnsley.
Billy Clarke passed a fitness test on his injured ankle and started up front alongside Alan Lee with Richard Naylor coming in at the back for the injured Matt Bates, who has returned to Middlesbrough.
Owen Garvan was handed his first start with Sylvain Legwinski suspended and started brightly in midfield, twice getting in the right position to clear from Morten Bisgaard.
Jon Stead fired wide with the first real strike at goal, then Michael Johnson sent a shot over the bar from inside the Town box.
Clarke sent a header wide from a Roberts' free-kick, while at the other end a Giles Barnes cross narrowly evaded Bisgaard at the far post.
Price saved well from Stead before the game burst into life seven minutes before the break, Howard having the ball in the net only for referee Ray Lee to award a free-kick for a foul by the striker on Jason De Vos.
Less than 60 seconds later, Blues were ahead, the on-loan from Accrington Roberts thundering in a 25 yard volley to register his ninth goal of the season but his first in Town colours.
Walton picked up his first booking for kicking the ball away at a free-kick and was quickly followed by Garvan as Derby started the second-half on top. Stead had already tested Price with a drive before Howard levelled the scores with a trademark header from Bisgaard's corner.
Seth Johnson was then cautioned for a late challenge on Garvan as the temperature was turned up, and it was increased even further as Walton's rash challenge saw him dismissed.
Lupoli replaced Seth Johnson on the hour as Derby looked to capitalise on the extra man and the on loan from Arsenal striker showed great skill to bring out a fantastic save from Price.
Michael Johnson and Lee were both yellow carded as the game maintained its intensity, with Gavin Williams, on earlier for Clarke, and Sito both playing a second game in successive nights following their run out against Needham Market last night.
Lupoli provided the main danger moments for Derby as Town were forced back, flashing a shot wide, then Bisgaard almost converting his cross at the far post.
Garvan sent a free-kick just wide after Lee had been brought down by Michael Johnson on the edge of the box as the game entered added on time.
Lupoli's magic weaved his way past three defenders in the final seconds to win a corner and the Italian was then left free to head in the winner after Michael Johnson's knock on, leaving the Town players holding their heads in total dismay again.
Town: Price, Bruce, De Vos, Naylor, Harding, Roberts, Walton, Garvan, Richards, Lee, Clarke (Williams 60). Subs not used: Supple, Haynes, Sito, Macken. Sent-off: Walton. Booked: Garvan, Lee.











