Once again though, Preston failed to keep a clean sheet which has cost them dear so many times this season. Rob Hulse who has been a thorn in Preston's side before opened the scoring after just eight minutes for Derby.
Mellor then missed a sitter before Wallace was pulled down int he box. Davidson converted the spot kick to bring North End back level.
Just before the half hour mark Mellor took advantage of the home sides frailties by nudging North End into the lead but his goal was cancelled out moments later thanks to a Jordan Stewart strike.
Preston now return to Deepdale for a match in front of the Sky cameras hoping to continue their good run of recent form and try to establish themselves int he race for a play off place.