Mendez-Laing’s first half goal made the difference on the day as United huffed and puffed but couldn’t find a way past a stingy Rams defence.
The result leaves United still in control of their destiny, but also still in need of another result to make sure of safety this season.
Garry Monk named four changes from Tuesday’s game against Bristol Rovers, as Gassan Ahadme, Jordan Cousins, James Gibbons and Ryan Bennett were all drafted into the starting line-up. Lyle Taylor returned from injury to make the bench.
Buoyed by their sold-out away contingent and with automatic promotion on the line, Derby made a strong start to the match and almost went ahead on 10 minutes, as Sibley’s corner almost flew all the way in, but for Mannion’s outstretched hand which pushed the ball onto the crossbar.
United responded well though, and should have took the lead themselves just five minutes later, as Ahadme stepped inside before firing at goal, only to see Wildsmith get in the way to deny the breakthrough.
The ever-dangerous Mendez-Laing was making the United defence work and after getting down the by-line on 34 minutes, his zipped ball across the box had to be expertly turned away by Ibsen Rossi.
He crashed a ball off the crossbar from 20 yards out with five minutes to go in the half, and moments later, he finally made the difference, as he latched onto a through-ball behind the United defence, before taking it past Mannion to slide into an empty net.
The U’s headed into the break behind, but still well in the contest, and began the second half on the front foot. Jordan Cousins let fly from the edge of the box 10 minutes into the restart,
It was all United on the hour mark but despite significant pressure on the Rams defenders, the opposition were able to block everything that came their way.
Garry Monk turned to the bench with 10 minutes to go, as Lyle Taylor and Sullay Kaikai entered the fold, joining Jack Lankester who had been brought on not long earlier.
Six minutes of added time were awarded, and the U’s kept on going, a long ball into the box was headed across goal by Bonne, but nobody was there to finish it off as United were denied a route back and Derby took the points back to the East Midlands.
