John Mousinho said Portsmouth “got everything wrong” as their four-game unbeaten run ended with a 4-0 thrashing at Derby.
Pompey missed the chance to pull clear of the Sky Bet Championship relegation places as they turned in a dismal display, with the hosts ending their own six-game winless run in style in front of a delighted Pride Park.
Kane Wilson, Eiran Cashin and Ebou Adams all struck before half-time as the Rams ran rampant in the opening period.
The visitors enjoyed plenty of possession but never threatened to get back into the contest and the result was put beyond doubt by Marlon Pack’s own goal midway through the second half.
Mousinho said: “It’s difficult to figure out where that came from – we weren’t expecting it. Going into the game I felt pretty confident.
“We’ll have to unpick it over the weekend and go again. A bit of a strange one.
“It wasn’t very good, to say the least. We got exactly what we deserved and maybe got off slightly light.
“The start was really poor, we invited too much pressure. We never really settled into the game.
“We went 1-0 down and settled into the game a little bit but then concede from a set-piece. It felt like every time they went forward they scored.
“A lot of disappointing parts of the performance. The most disappointing thing is that we seemed to get everything wrong. Tactically as staff, but I think you can master that if you’re brave and win your individual battles and win second balls, defend your box properly – we didn’t do any of that.”
Both teams played out goalless draws in midweek but it took Derby only eight minutes to open the scoring as Nathaniel Mendez-Laing fired in a low cross and Wilson ghosted in at the back post to fire past Nicolas Schmid.
Kenzo Goudmijn’s corner was headed home by Cashin midway through the first half and Craig Forsyth squared for Adams to bundle home a deflected third inside the opening half-hour.
The result was put beyond doubt when Marcus Harness got clear down the right against his former club after 65 minutes and saw his low cross turned into his own net by Pack.
Derby spurned several opportunities to inflict further damage as Pompey failed to muster a shot on target.
Paul Warne said: “I think we’ve played better in other home games, weirdly, but goals change games and I thought we started really well – I was pleased with that.
“We scored and I’ve always been critical of our play in the final third that we don’t pick the right pass but tonight we did.”
