It was an immediate return to the points after the weekend defeat at home to Norwich and the result lifted Boro back to a seventh spot and leaves the visitors stranded to the foot of the table.

Neil Warnock had moved to shuffle his pack and handed a debut to new signing Duncan Watmore as Boro played the second in a run in a nine games in 28 days. 

Assombalonga brought out a great save from David Marshall inside the first five minutes after good work from Marcus Tavernier and Patrick Roberts, and the Boro captain went on to have a decisive say in the game by scoring a goal in each half.

Anfernee Dijksteel got an important touch a cross into the box with Kamel Jozinar well-placed while Paddy McNair was also first to another decent ball into the Boro box to clear any danger.

But there were times when Derby didn’t know whether to stick or twist when Warnock’s side pressed hard and high, and Marc Bola hooked a shot wide after one concerted spell of Boro pressure.

Derby’s first shot came on 30 minutes when Max Bird tried his luck from the edge of the area with an effort which was wide of Marcus Bettinelli’s upright.

Moments later, Boro were in front, though, courtesy of Assombalonga. Jonny Howson sent in a great cross, Watmore headed towards goal, and Assombalonga was on hand to force the ball home from close range.

It was almost 2-0 within minutes when Assombalonga turned and shot just wide after more Boro pressure, and the Boro striker also curled a free-kick just wide of the mark after George Saville was fouled on the edge of the box.

Louie Sibley sent one wide early in the second half while Tavernier also drilled one wide after Nathan Byrne went in the book for a foul on Watmore.

Boro made a double change on the hour, introducing Djed Spence and Marvin Johnson for Watmore and Roberts as the game opened up and the visitors suddenly looked more of a threat. 

Bettinelli made a couple of good reaction saves after Sibley appeared to floor McNair, before Tavernier picked out Dijksteel with a great ball, but he couldn’t apply the finishing touch.

Saville also hooked a Dael Fry ball into the box wide, and the same player also sent another one just wide. Marshall also denied Tavernier with a reaction block, but it was 2-0 with 19 minutes remaining when Assombalonga bagged his second of the night.

Bola and Johnson combined before Tavernier turned the ball goalwards and Assombalonga fought to claim the final touch on the line.

It was 3-0 with seven minutes remaining when Johnson scored a terrific solo goal, cutting in before curling the ball beyond Marshall to put the result beyond doubt. 

The Derby goalkeeper prevented Spence from adding a fourth as Boro looked to rub salt into the wounds of the visitors and their interim managerial quartet of Wayne Rooney, Liam Rosenior, Shay Given, and Justin Walker.