Millwall maintained their impressive record at Pride Park with a 2-1 victory to dent Derby’s hopes of Championship survival.
Goals in the first half from Jed Wallace and Tyler Burey gave Millwall control and although Jake Cooper put through his own net late on, they saw the game out to complete a fifth victory in the last seven visits to Derby.
Derby had plenty of the ball but could not break down a well organised and disciplined Millwall team who could have scored more goals.
Burey wasted a great chance before he netted and former Derby defender Scott Malone could have got on the scoresheet late on.
Victory for former Derby boss Gary Rowett moved Millwall up to 12th while defeat left Wayne Rooney’s side eight points adrift of safety.
With Tom Lawrence serving a three-match ban for his red card on Saturday, Derby brought in Louie Sibley, who scored a hat-trick at Millwall two seasons ago, but the visitors scored with their first attack.
Derby conceded a free-kick out on the left and Wallace’s whipped delivery evaded everyone and nestled inside the far post.
The home side responded with Max Bird firing just over before Lee Buchanan’s drive was deflected behind for a corner but Millwall should have scored again in the 24th minute.
Derby gave the ball away and Wallace broke clear on the right to set up Burey but the striker fired over from 10 yards.
Burey made amends six minutes later when former Derby midfielder Mason Bennett pulled the ball back from the left and after Wallace’s shot was blocked, Burey buried the rebound.
Derby almost hit back with Festy Ebosele shooting against the legs of Bartosz Bialkowski before Jason Knight got in on the right but fired wide.
But Millwall were good value for their half-time lead and Derby made two changes for the second period with Colin Kazim-Richards and Ravel Morrison replacing Sibley and Ebosele.
Derby started strongly with Knight having a shot blocked and Luke Plange sending a free-kick from just outside the area over the bar.
It was Derby having the bulk of possession but Millwall were holding their shape and denying them any clear openings.
Bialkowski did well to punch clear under pressure from Kazim-Richards but Millwall broke dangerously with Malone shooting over at the back post when he should have hit the target.
Millwall had been solid at the back but they handed Derby a lifeline in the 89th minute when Cooper sliced an attempted clearance into his own net.
But it was too late for Derby who could not fashion another chance and remain deep in trouble in the relegation zone.
‘The pure simplicity of the way Slot has managed the squad is probably the biggest thing I could say about him. It’s not broken, so let’s get on with it’: Liverpool legend full of admiration for Jurgen Klopp's successor at Anfield
‘I trained at Spurs and thought they’d give me a chance. But I received a letter thanking me but saying they didn’t think I was good enough – I was gutted’: How Tottenham missed out on signing Wales legend John Toshack
