A determined display at the back wasn't enough to earn a point for ten man Reading against the Rams this evening after Tom Ince's toe-poke proved enough to take all three points at Madejski Stadium.
A relatively even game tipped in Derby's favour on the stroke of half-time when striker Orlando Sa was sent off for an off the ball incident with Jason Shackell and despite a good rearguard action from Steve Clarke's men, Ince stabbed home the winning goal with 20 minutes to go.
Steve Clarke made just one change to the side that demolished Ipswich on Friday night, bringing in Michael Hector for Anton Ferdinand at the back, whilst adding Jake Cooper to his substitutes bench.
In only the second minute, midfielder Aaron Tshibola had a well-hit effort charged down after Derby had failed to clear a corner from the right. But Derby signalled their intent to attack moments later when a break away was led by the lively Johnny Russell and Jeff Hendrick's effort whistled wide from the edge of the area.
Nick Blackman, oozing with confidence, saw a swerving shot from 30 yards out parried wide by Scott Carson, then Blackman teed up Quinn who dragged an effort wide of the bottom right corner. And with eight minutes on the clock, a nice move involving Vydra and Blackman almost released Tshibola into a goalscoing position, only for the midfielder to slip and scuff his effort on goal.
Two fantastic sliding blocks denied Jacob Butterfield midway through the half - Michael Hector charging his initial shot down before fellow centre-back Paul McShane slid in to deny the midfielder once more with a rasping follow-up.
At the other end, the home crowd were in good voice after some high pressing from the home side won possession back and Oliver Norwood unleashed a powerful low drive from distance that Carson did well to turn around the right post.
On the stroke of half-time, Reading's hopes of back-to-back home wins took a blow when Orlando Sa was shown a straight red card for an off the ball incident with Jason Shackell, who was also shown a yellow card.
Half-time: Reading 0 Derby County 0
The Rams came out of the blocks fast, looking to take advantage of the extra man and Hector had to slide in to intercept Russell's low cross looking for Martin in the middle. Cyrus Christie then came close with a curling effort that sailed just wide of the top left corner.
The Royals remained positive at the other end however, and on the hour Blackman cut inside from the right, beating one man and then drilling low towards the bottom right corner but this time wide of Carson's goal.
Michael Hector meanwhile in his haste to clear another Derby attack clattered into Tshibola, who thankfully was hauled to his feet by Hector unhurt.
Derby, however, took the lead moments later when the ball founds its way through to the feet of Tom Ince
who neatly toed the ball past the dive of Jonathan Bond to hand the visitors the lead.
Reading looked to respond, but Norwood's effort from distance was watched wide by Carson with a quarter of an hour remaining. Then Nick Blackman took aim with a set piece from fully 25 yards out and it sailed high over the crossbar.
Craig Forsyth came close to putting the game to bed, arrowing just over the bar from a narrowing angle as he burst onto the ball down the left side of the Royals box.
Reading refused to give up on their unbeaten run and substitute Williams saw a late strike charged down, before a combination of McShane and Robson-Kanu connected with a Norwood corner to head just over.
Five minutes of injury time were signalled and at the death McCleary dinked a lovely ball into the run of Gunter who volleyed at goal but over, a difficult chance as the ball dropped over his shoulder.
There was no way back thought and Reading's unbeaten streak had been ended.
Full time: Reading 0 Derby County 1
: Bond, Gunter, Obita, McShane (c), Hector, Norwood, Tshibola (McCleary 80), Quinn (Robson-Kanu 68), Blackman, Vydra (Williams 63), Sa.
Unused subs: Al Habsi, Cooper, Piazon, John.
Yellow: Tshibola, Norwood.
: Carson, Christie, Forsyth, Keogh, Shackell, Butterfield, Hendrick (Bent 61), Johnson, Ince (Weimann 84), Martin (c), Russell.
Unused subs: Grant, Warnock, Pearce, Hanson, Dawkins.
Yellow: Shackell, Johnson
Referee: Mr A Davies
Att: 15,687 (1,293 away)