Two late goals handed Huddersfield a deserved 2-0 win against a Derby side who played for 87 minutes with 10 men.
The Terriers moved back into the Championship play-off places after finally breaking the Rams’ dogged resistance in the final 15 minutes through goals from Duane Holmes and Jordan Rhodes.
The Rams’ bid to continue their recent revival – they had lost just one of their previous seven games – was severely dented after only three minutes when former Terrier Richard Stearman was sent off.
The defender – signed from Huddersfield just last summer – dived in with a studs-up challenge on Lewis O’Brien just outside the Derby box and referee Matthew Donohue went straight to his top pocket.
Sorba Thomas fired the resultant free-kick inches wide via the slightest of deflections.
Danny Ward then guided an angled effort just off target as the hosts continued to seek swift punishment.
Rams boss Wayne Rooney was clearly in for a testing night now, and Huddersfield threatened again when ex-Derby midfielder Holmes forced Ryan Allsop into a decent save.
Holmes lashed a half-volley over the top and centre-back Tom Lees nodded just past the post, but by the half-hour mark there was still no breakthrough.
Gutsy Derby then went close themselves when Louie Sibley fizzed a low, angled strike just past the far post.
As the game wore on, the visitors were looking more comfortable when in possession, and that in turn led to a lull in Huddersfield’s forward momentum.
In the 40th minute the Terriers almost broke the deadlock, with Holmes this time guiding another close-range effort a whisker off target following a neat flick from O’Brien.
The Rams dug in until the interval, and then after the restart were probing for an opening.
So were Huddersfield, with manager Carlos Corberan bouncing around enthusiastically on the touchline, but it remained scoreless as the hour mark approached.
Both sets of fans were doing their best to rally their respective troops, and Sibley suddenly raced clear of the Huddersfield back line, but he took a heavy touch and goalkeeper Lee Nicholls was able to charge out and clear the danger.
With Derby packing their defence, the hosts appeared more and more frustrated, with Rooney’s battlers now eyeing a potentially precious point as the clock continued to tick.
With just 18 minutes left Huddersfield carved out a rare half-chance, only for O’Brien to drag a disappointing left-foot shot wide from 15 yards.
However, the hosts finally got the fortunate break they probably needed just three minutes later.
It was Holmes who struck, as his 20-yard shot following debutant substitute Carel Eiting’s pass flicked off Krystian Bielik before looping agonisingly over the outstretched arm of Allsop.
Four minutes later Huddersfield’s victory was finally sealed when substitute Rhodes mopped up after Allsop could only parry Ward’s thunderous strike, leaving Derby seven points from safety.
