Two late strikes from Jesse Lingard and substitute Romelu Lukaku ensured the Reds progressed to the Emirates FA Cup fourth round with a thoroughly deserved 2-0 win over a stubborn Derby County under the bright Friday night lights of Old Trafford.
Mourinho received a double Belgian boost as Romelu Lukaku returned to the matchday squad having sat out the win against his former club Everton with a head injury, whilst Maroune Fellaini did likewise after having failed to feature since the win over Brighton here back in November. Both took their places on the Reds' substitutes bench.
For the first time since United's opening home league game of 2016/17 against Southampton, it was Friday night football under the lights at Old Trafford and it was a great spectacle.
The Reds started equally as brightly, with Pogba continuing his impressive form which had previously helped his side defeat Everton on New Year's Day. The Frenchman crossed for another in-form player, Lingard, to fire over, before then shooting inches too high himself after positive build-up play.
Chris Smalling, who returned to United's defence after picking up a knock against Leicester, made some crucial early interceptions as Gary Rowett's Derby looked to play on the counter attack at every opportunity. Reds academy graduate Tom Lawrence often provided the Rams' impetus, looking to impress on his Manchester homecoming.
Marcus Rashford should have put United ahead 18 minutes in after clever footwork took him away from two Derby defenders, but the youngster blasted just over from 15 yards.
Juan Mata had a 20-yard free-kick tipped away by Carson, before Sergio Romero did likewise at the other end as Marcus Olsson's header looked destined to loop in.
If Rashford's earlier attempt was a good goalscoring chance, then his next effort was an even bigger one. A pinpoint Henrikh Mkhitaryan cross was met with a deft header at the back post by United's number 19, but he could only strike the post when he should, in truth, have opened the scoring.
Pogba then replicated what Mata had done moments earlier with what looked like an inch-perfect free-kick, but again Carson was equal to it, diving to his right to acrobatically push the ball over the crossbar and the sides went into the break on level terms at 0-0.
United 2 Derby 0 Gallery
The standout photos from our Emirates FA Cup third round win.
United continued to probe and Pogba again shot inches wide before Carson and then the post denied Rashford for the second time.
Lukaku and Anthony Martial, who had replaced Mkhitaryan and Mata, combined as the latter crossed for the Belgian who headed against the post, but the linesman had his flag raised anyway.
Lingard was the next to be denied by Carson who was fastly becoming the Rams' hero, before Pogba fired the rebound wide. But the young man from Warrington who is in the form of his life was not to be denied this time as substitute Martial fed Lingard who unleashed a fierce effort into the top corner from 25 yards for his 11th strike of the season and his eighth goal in his last 10 appearances.
Lukaku then put the game to bed in the final minute of regular time, as he first brought the ball down on the halfway line, played a one-two with Martial, before slotting through the legs of Carson.
United: Romero; Lindelof, Smalling, Blind, Shaw; Herrera, Pogba (c), Mata (Martial 67), Lingard, Mkhitaryan (Lukaku 45); Rashford (Fellaini 79).
Subs not used: Pereira, Darmian, Rojo, McTominay.
Derby: Carson, Wisdom, Pearce, Keogh (c), Olsson; Weimann, Thorne, Huddlestone, Russell (Hanson 78), Lawrence, (Bennett 81); Winnall (Vydra 67).
Subs not used: Mitchell, Baird, Martin, Nugent.
“Until you score, it's difficult. I think this was one of our best games of the season. Everyone was feeling part of the game, moving the ball. I think we played amazing. But if you don't score, the game is always open and that's what happened. We deserved to win by more goals. We can be optimistic with the second half of the season. We are Manchester United. This club is about titles.”
WHAT'S NEXT FOR UNITED?
The Reds now have a well-earned break before we are back at Old Trafford to face Stoke City. The game is scheduled for Monday 15 January in the Premier League with kick-off at 20:00 GMT but if Stoke are taken to a replay in the FA Cup by Coventry City, the match will move to Saturday 13 January at 12:30 GMT.