Derby County produced one of their poorest displays of the season as they fell to a 1-0 defeat at home to struggling Millwall on Wednesday night.
Jed Wallace got the winner on 73 minutes with the visitors' only shot on target, the Rams not managing one of their own until the dying moments of the game.
It was a Derby display devoid of any urgency or quality, a switch to 3-5-2 producing little in the way of inspiration and the fans left frustrated and exasperated by their team that looked tired and leggy from minute one.
Millwall deserve credit for sitting tight and going in for the kill when they had the chance, but in truth their well-organised defence was barely seriously tested.
It will leave much for Frank Lampard to think about as the Rams prepare to head to Nottingham Forest on Monday, with a win badly needed to keep any play-off hopes on track.
A largely sedate opening ten minutes saw neither side making much in the way of openings in the final third, Derby's patient approach threatening to create but Millwall holding firm.
The first effort on goal didn't come until 18 minutes in as Harry Wilson's flicked header from a Duane Holmes cross floated harmlessly wide.
Then Martyn Waghorn received the ball in the penalty area but couldn't get a shot away and was hounded out by defenders.
Tom Huddlestone had a crack from 30 yards five minutes before the break which was a few feet too high, but a dreadful first-half ended with neither a goal nor much to shout about whatsoever.
Richard Keogh flicked a corner wide of the post in the opening moments of the second-half, then Jack Marriott got free and in towards goal but fluffed his lines at the key moment and the ball was cleared.
Wilson arrowed a 30-yard free-kick well over the top as still neither side could test the opposing goalkeeper, and it remained that way until the 73rd minute.
Derby made a mess of an attacking free-kick leading to Millwall breaking away at pace and Shane Ferguson sending Jed Wallace in on goal and he fired low and under the diving Kelle Roos and into the net.
The Rams offered precious little in response.
Their first effort on target came in stoppage time when Fikayo Tomori's header was kept out by Jordan Archer, sub Florian Jozefzoon following up with a volley that was blocked.
But that would be that. Derby offered nothing else in reply despite three changes and the visitors were able to hold on to their lead with worrying ease as far as the Rams were concerned and the boos rang out at the final whistle from the disgruntled home faithful.
Derby: Roos, Bryson, Tomori, Keogh (c), Wilson (Nugent 86), Waghorn, Marriott, Holmes, Cole (Jozefzoon 73), Bogle, Huddlestone (King 73)
Subs not used: Ravas, Wisdom, Johnson, Malone
Millwall: Archer, Hutchinson (c), Cooper, Williams, M Wallace, Gregory (Elliott 75), Ferguson, Romeo, J Wallace (Tunnicliffe 88), Leonard, Marshall
Subs not used: Martin, Thompson, Onyedinma, Morison, O'Brien
Ref: James Linington`
Goals: Millwall - J Wallace 73
Star Ram: Duane Holmes