Derby's play-off hopes suffered another blow when they squandered a two-goal lead to lose 4-3 at home to Cardiff City in another roller-coaster match at Pride Park.
Steve McClaren's team had come from three goals down to draw with Bristol City at the weekend but this time they were cruising when Julien de Sart's first goal for the club and another from Darren Bent put them in front inside 17 minutes.
But this time it was Cardiff who hit back through a Kedeem Harris brace either side of half-time before a great strike by Craig Noone put the visitors in front.
Bent headed an equaliser only for Cardiff to have the final word when Joe Ralls coolly converted a last-minute penalty to leave Derby adrift of the top six.
Cardiff named the team that won 2-0 at Leeds on Saturday but Derby made three changes from the draw against Bristol City
Midfielders Bradley Johnson and Craig Bryson were missing with injuries while winger Abdoul Camara was left out because he is about to become a father.
Derby had been awful in the first half against Bristol City but they went ahead in the seventh minute when Allan McGregor parried an Alex Pearce header and De Sart put the rebound in from inside the six-yard box.
It got even better for the home side 10 minutes later when Cardiff's defence was wrong-footed by a mishit shot from Tom Ince and Bent took advantage to lift the ball over McGregor from eight yards.
Cardiff almost hit back immediately when Harris burst through on the left and forced Scott Carson to turn his angled drive behind but Derby were moving the ball well and were close to a third in the 26th minute, this time Bent' seeing his shot deflected for a corner.
McGregor made another good save after Ince cut inside from the right in the 31st minute but was relieved to see a Will Hughes strike dip just wide as Derby again found space around the Cardiff box.
But the visitors got a foothold in the game in the 41st minute when the ball dropped for Harris on the edge of the area and his volley took a deflection to loop over Carson.
It was Harris again who pounced at the start of the second half when he smashed the ball in after a long throw from Aron Gunnarsson was flicked on and the game was turned on its head in the 57th minute when Noone lashed a shot past Carson from 20 yards.
But the match was so open more goals were inevitable and Derby equalised in the 74th minute when Marcus Olsson crossed from the left and Bent headed past McGregor from eight yards.
Derby looked the more likely side to win it but Cardiff broke up the right and substitute Rhys Healey was tripped by Alex Pearce and Ralls sent Carson the wrong way with the spot-kick.
Source : DSG