Jack Marriott scored the only goal as Derby picked up three Sky Bet Championship points at a Wigan side who played with 10 men for 75 minutes following the dismissal of left-back Kal Naismith.
Referee Gavin Ward had no option but to brandish red after only 15 minuets when last man Naismith allowed Harry Wilson to get the wrong side, and ended up pulling him down as he attempted to shoot from the edge of the area.
And Marriott popped up within five minutes to send a clever header past Christian Walton to decide a decent game played in almost-torrential rain at the DW Stadium.
Derby were first to threaten with Jayden Bogle cutting inside Naismith and shooting for the near post, only for Walton to help it round for a corner.
Wigan too were quickly into their stride, and wonderful interplay between Naismith, Sam Morsy and Josh Windass released Gary Roberts, whose cross narrowly evaded James Vaughan who would have had a tap-in.
But the home side were rocked with barely quarter-of-an-hour gone when they were reduced to 10 men with Naismith receiving a straight red card.
The resulting free-kick from Wilson came to nothing but the respite was only temporary as Derby took the lead with their next attack.
Bogle supplied the cross from the right, and Marriott was on hand to nod it past Walton at the far post.
It was almost 2-0 moments later, with Nathan Byrne clearing off the line to deny Wilson.
Wigan made a double change, sending on Callum Connolly and Darron Gibson for Gary Roberts and Vaughan, and switching to a 5-3-1 formation to stem the bleeding.
But still Derby pressed with Tom Lawrence firing just over and Mason Mount forcing a brilliant save from Walton.
There was a flashpoint as Wilson and Wigan skipper Morsy went head-to-head on the edge of the home box, with both players given a yellow by the official.
To Wigan's credit, they ended the half on top with Reece James firing a free-kick straight at Scott Carson, and Byrne sending over a superb cross within moments of the restart that deserved better.
James then advanced from wing-back to shoot straight at Carson, before the Wigan players were incensed when Wilson went to ground in the box from little or no contact from Dan Burn, and was perhaps extremely fortunate not to pick up a second booking.
The Wales international was withdrawn at the next break in play as Derby tried to hold on to what they had.
The 10 men of Wigan never gave up the ghost, but the Rams were able to hold on to secure another three precious points.