Jose Mourinho was given a bloody nose by his former midfielder Frank Lampard as Derby deservedly sent 10-man Manchester United crashing out of the Carabao Cup on penalties.

A night that started with fresh questions over Paul Pogba’s future ended with one of the best players that the Portuguese has ever worked with securing the finest win of his short managerial career.

Derby looked to have secured victory inside 90 minutes after substitute Jack Marriott followed up the exceptional Harry Wilson free-kick that cancelled out Juan Mata’s early goal, only for Marouane Fellaini to direct home deep into stoppage time to snatch a 2-2 draw.

But former Liverpool goalkeeper Scott Carson proved the Sky Bet Championship side’s shootout hero, saving Phil Jones’ attempt to secure an 8-7 triumph at a stunned Old Trafford.

Few could have foreseen things heading the Rams’ way given the way this third-round tie started, but the inability of United, in particular Romelu Lukaku, to add to Mata’s goal proved as costly as their failure to shackle Derby.

Lampard’s men were bold and brave even when behind, eventually drawing level through a 30-yard free-kick by Wilson – the Liverpool loanee whose run would soon lead to Sergio Romero’s sending-off for handling outside the box.

Marriott looked to have snatched a deserved late winner, only for Fellaini to head home and take the match into penalties where the visitors would prevail.

Derby celebrate their cup triumph
Derby celebrate their cup triumph (Martin Rickett/PA)

It was a meek response to United’s weekend draw with Wolves as Mourinho’s much-changed side failed to make their mark.

Pogba watched from the stands as the evening began brightly enough.

Lukaku had already got a header on goal before flicking Anthony Martial’s pass into the path of Jesse Lingard in the third minute. The England international smartly laid off to Mata, who bent a low left-footed strike home to the delight of Mourinho.

Romero raced off his line to prevent Mason Bennett directing in Mason Mount’s defence-splitting pass, but United should have put the game to bed soon after.

Jose Mourinho and Frank Lampard watch on
Jose Mourinho and Frank Lampard watch on (Martin Rickett/PA)

Mata met a ball with a fine touch and saw a strike turned wide by Carson, who was left flapping from the resulting corner as Ashley Young’s delivery hit the near post.

It was a frantic opening 15 minutes that should have seen Lukaku score, especially after robbing Derby captain Richard Keogh before thrashing wide poorly.

Lukaku was unable to stretch to meet a fine clipped cross by Martial and Eric Bailly flicked wide from a corner routine – missed chances that were giving hope to Derby, who Lampard had playing with positivity in a first half that saw Craig Bryson go close.

Wilson saw an attempt bobble just wide after a fine Romero stop early in the second half, but the 21-year-old and his team-mates would not be denied for long.

Stepping up to a free-kick 30 yards from goal, Wilson struck with power and swerve to leave Romero motionless as the ball flew into the top left-hand corner.

Derby's Harry Wilson fires home a free-kick at Old Trafford
Derby’s Harry Wilson fires home a free-kick at Old Trafford (Martin Rickett/PA)

Derby had the momentum and Wilson soon got on the end of a long ball, leading Romero to handle outside the box.

Referee Stuart Attwell showed a straight red card to the goalkeeper, leading third choice Lee Grant to come on for his debut against his former club.

Lukaku sent a shot off the post and Martial bent just wide as United looked to change the dynamic, but County were still threatening at the other end.

Grant showed great reflexes to tip substitute Florian Jozefzoon’s effort wide, but he would be beaten in the 85th minute as Marriott reacted quickest to turn home after Mount’s attempt was stopped.

Many United fans headed for the exit as their hopes of a leveller looked set to fall short, only for Fellaini to bundle home Diogo Dalot’s fine cross in front of the Stretford End deep in stoppage time.

But the hosts’ disappointment would only be delayed.

Jones was the eighth United player to take a spot-kick and the first person to fail, with Carson’s low save sending Derby wild.