The Blues found themselves 3-0 down after 29 minutes against a side which had won one of their previous 11 matches – and it only got worse.
John Mousinho’s men fully deserved their 4-0 humiliation – and here are our Pompey player ratings...
1. Nicolas Schmid - 5
A couple of late stops including dramatically clawing one out as it threatened to trickle in. Wasn’t helped by his team-mates. Photo: Jason Brown
2. Terry Devlin - 4
(Replaced by Zak Swanson on 46 mins) A tough, tough evening. Had his hands full dealing with Mendez-Laing, with two of Derby’s three goals which arrived when the right-back was on the pitch involving the winger. One to forget. Photo: Jason Brown
3. Marlon Pack - 5
Unfortunate own goal for Derby's fourth and had some decent moments, but was simply part of a defence which really struggled. Photo: Jason Brown
4. Tom McIntyre - 3
Recalled to the side in place of Poole and endured a dreadful evening. Little went right for the centre-half, including Adams’ goal deflecting off him to put Derby 3-0 up. Should have done far better for the fourth too. Photo: Jason Brown