Derby sunk to the bottom of the Championship after a 1-0 defeat at Middlesbrough extended their winless to run 12 league games.
The Rams looked set to battle to what would have been a crucial point at the Riverside Stadium but Finn Azaz struck the winner for Boro 10 minutes from time.
John Eustace has lost his first three games since taking charge and Derby are now four points adrift of Championship safety.
Azaz’s 10th goal of the campaign ensured Boro closed the gap to the play-off places to just two points after securing back-to-back victories for just the third time this season.
Despite their recent struggles, it was the visitors who were first to threaten when captain Ebou Adams’ curling strike from distance was well kept out by Mark Travers.
Derby were happy to let Boro have the ball and the hosts came closest to a breakthrough when Marcus Forss’ low drive was well saved by Jacob Widell Zetterstrom. The forward got a second bite at it when the ball landed back at his feet but was this time denied by Sondre Langas, who made a good defensive block.
Just moments later, ex-Derby forward Morgan Whittaker curled just wide from the edge of the box as Boro continued to dominate possession but struggled to create clear-cut openings.
A teasing Azaz delivery from the left was headed over his own crossbar by Craig Forsyth and Whittaker had another go from outside the box five minutes before half-time but was again off target.
Derby then conceded possession inside their own half and Aidan Morris worked it to Forss on the right but the forward’s shot was deflected behind. Dael Fry headed over from the resulting corner.
Azaz very nearly broke the deadlock in first-half stoppage time when his left-footed effort from the edge of the box hit the outside of Zetterstrom’s right post.
Derby were brighter at the start of the second half and Fry came to Anfernee Dijksteel’s rescue when the right-back made a mess of an attempted header back to goalkeeper Mark Travers.
With George Edmundson and Rav van den Berg already out injured, Boro suffered more defensive injury woe when Luke Ayling was forced off on the hour mark. Ryan Giles was brought on and left-back Neto Borges had to move across to play at centre-half.
Boro looked to be running out of ideas but forced the breakthrough 10 minutes from time.
Morris pounced on some uncertainty in the Derby defence and crossed for Tommy Conway. The striker’s shot was blocked but Azaz was on hand to fire home the rebound.
