Derby continued to climb away from the Coca-Cola Championship drop zone and increased Nottingham Forest's relegation fears with a comprehensive 3-1 victory over their east midlands rivals at the City Ground.
Lewin Nyatanga volleyed the visitors ahead after only five minutes with his first Rams goal for almost two years. Derby doubled their lead through a more likely source two minutes into the second half when Rob Hulse headed his 14th goal of the season.
And Nigel Clough's side sealed a fourth straight league win after 67 minutes with Steve Davies' coolly-taken penalty. Robert Earnshaw scored against his former club three minutes from time but it was merely a consolation goal for Forest.
It was Derby's second triumph at the City Ground this month after knocking Forest out of the FA Cup in a fourth-round replay on February 4.
The visitors took an early lead through Nyatanga's first goal for the club since April 2007. Luke Chambers needlessly fouled Hulse in the left-hand channel. Former Forest winger Kris Commons swung in a free-kick that was met by both Chambers and Nyatanga on the penalty spot, causing the ball to loop up into the air. Nyatanga reacted quickest to the loose ball and hit a left-foot volley into the bottom corner from 10 yards.
Derby's good start was overshadowed by an injury to Nacer Barazite. The on-loan Arsenal winger appeared to hurt his arm in a sliding challenge and had to be replaced by Mile Sterjovski after 16 minutes.
Derby doubled their lead when Hulse scored a second goal soon after the restart. Another silly foul on the left, this time by Wes Morgan on Sterjovski, gave Robbie Savage the chance to whip-in a superb cross and Hulse glanced his header past Paul Smith from six yards.
And it was 3-0 midway through the second half when Hulse was pushed in the back by James Perch as he threatened to convert Paul Connolly's cross. Davies stepped up to roll the spot-kick into the bottom corner and that was the cue for some Forest fans to head for the exits.
The Rams finished the game with 10 men after James McEveley suffered an arm injury and could not continue. Clough had already used his three substitutes.
Forest were able to capitalise on their numerical advantage and pulled a goal back when Earnshaw headed home Garath McCleary's right-wing cross.
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