Sunderland kept up the pressure in the race for an automatic promotion place after surviving intense late pressure from a Rams side struggling to avoid relegation.
The Black Cats stormed into a two-goal lead through John Oster and Tommy Smith but after skipper George McCartney needlessly handled in the penalty area, they were forced to hang on for a third successive victory.
Rams skipper Ian Taylor sent goalkeeper Mart Poom the wrong way from the 63rd minute spot-kick and Paul Peschisolido was unlucky to have a shot diverted behind with the home defence struggling to cope.
The return of Julio Arca and Jason McAteer from injury gave Sunderland an advantage in midfield, with the former playing a big part in both goals.
Sunderland attacked from the outset with Gary Breen heading over and Darren Byfield firing into the side netting from a tight angle but only a brilliant double save by Lee Grant prevented a tenth minute lead.
The goalkeeper denied both Arca and Byfield and three minutes later Peschisolido was stretchered off after colliding with goalkeeper Poom. The diminutive striker, however, returned five minutes later looking none the worse for his mishap.
But Derby fell behind in the 31st minute, Grant saving well from Arca, only for Oster to pounce on the loose ball at the far post and score from close range.
The lead should have been cancelled out almost immediately but Manel, released by Leon Osman, fired into the side netting with the goal at his mercy.
Grant kept the Rams in the hunt with another excellent save. Smith skilfully worked his way along the byline and his low shot was destined for the bottom corner until the intervention of the inspired goalkeeper.
Grant had no chance in the 50th minute when Arca crossed from the left and Smith's looping header dipped just under the bar.
"It was a scrap,'' admitted manager Mick McCarthy. "We made life hard for ourselves by giving away the penalty. They had a go at us as you would expect.'' Derby manager George Burley was delighted with his side's spirited rally. "We could have folded at 2-0 but we didn't," he said. "We have to look to win all our games and hopefully we will have the will to scrap.''