Frank Lampard's Derby County suffered a blow to their Championship playoff hopes as relegation-threatened Millwall grabbed a vital 1-0 win at Pride Park on Wednesday.

Just Millwall's second away win in 18 Championship matches moves the FA Cup quarter-finalists five points clear of the drop zone, while Derby remain two points outside the top six.

Derby could have few complaints after a desperately flat performance despite Lampard's former Chelsea teammate Ashley Cole making his full debut and Millwall thoroughly deserved the victory secured by Jed Wallace's second-half strike.

After both sides' cup exertions at the weekend, neither goalkeeper was called upon in a poor first half.

Wallace skimmed the bar with a cross in the 55th minute but Millwall stunned the home side with a breakaway goal in the 72nd.

Shane Ferguson released Wallace who ran into the box before driving a low shot under Kelle Roos.