Wigan 2 Derby 0
By Richard Jolly
Last Updated: 01/01/70 1:00am
Ellington scored his 14th goal of the season when he headed an Alan Mahon cross past Rams keeper Lee Grant.
Mahon, with a long-range volley, and Ellington, with a 20-yard shot, had both come close before then while the striker had also been denied by Grant after a sharp turn.
Derby striker Noel Whelan had almost broken the deadlock with a thunderbolt which brought the best out of Latics keeper John Filan.
And Whelan's replacement Marco Reich created a chance for Izale McLeod to level for Derby in the sceond half, but he shot tamely at Filan with only the keeper to beat.
Wigan made them pay. Latics boss Paul Jewell brought McCulloch on for Roberts and the Scot volleyed in his fifth goal of the season from an Ellington flick-on.
On-loan defender Rob Edwards then wasted a chance to bring Derby back into the game and defeat leaves them one point and one place above the relegation zone.