The United striker gave the hosts an early lead when his powerful effort -- United's first attempt in the match -- bounced in front of Paulo Gazzaniga and inexcusably beat the Spurs keeper at his near post, only for Dele Alli's sensational effort to ensure the visitors were level at the break. But it was the impressive Rashford who had the final say, calmly sending Gazzaniga the wrong way from the spot to end Mourinho's three-game winning streak despite a late Tottenham rally in search of an equalizer.
Dele Alli's fantastic run of form continued with a strike that was nothing short of a wonder goal, while Gazzaniga responded to his early disappointment superbly with a series of confident stops, including a world-class effort to tip Rashford's dipping attempt onto the crossbar. Mourinho will be pleased with the character his side showed to bounce back and level the scores on a testing evening and the visitors can take confidence from their good fight late on despite defeat.
Tottenham faced one-way traffic during a first half that saw the London side face a Rashford-led on-slaught and struggle to escape their own half. The visitors fell behind cheaply as the Red Devils struck with their first attempt on goal and they gifted United a second from the spot when Sissoko was deemed to have tripped Rashford, bringing Spurs' six-game unbeaten run to an end.
Manager rating (out of 10)
Jose Mourinho, 5 -- December may be the month of Christmas cheer, but it was a miserable Manchester evening for the Spurs boss who suffered his first defeat since succeeding Mauricio Pochettino. His tactics didn't go to plan in the first half, but Spurs improved after the break and Mourinho has certainly reignited something within Alli in particular.
Player ratings (1-10; 10 = best, players introduced after 70 minutes get no rating)
GK Paulo Gazzaniga, 6 -- Got off to the worst possible start when he was beaten comfortably at his near-post by Rashford's early strike, which bounced awkwardly in front of the Spurs keeper. He bounced back with a string of sharp saves, thwarting Mason Greenwood with his feet and superbly flicking Rashford's deadly, dipping effort onto the bar.
DF Serge Aurier, 6 -- The Frenchman has continued to grow in confidence under Mourinho, showing excellent composure and strength to pivot away from Greenwood on the touchline in one tricky challenge. Aurier was dealt a tough and tiring task facing Rashford, but he stuck to it well at times and still managed to provide attacking value, including drawing a save from David de Gea prior to Alli's moment of magic.
DF Davinson Sanchez, 5 -- Acted quickly to shut out Jesse Lingard and snuff out a couple of early United attacks, but it was all too easy for Rashford to skip past the centre-back and rip a powerful strike past Gazzaniga. Try as he might, Sanchez struggled to find an answer to the United forward's questions.
DF Toby Alderweireld, 5 -- The centre-back didn't have his best game and was thankful to see Gazzaniga deny Greenwood after the United youngster fired through the Belgian's legs, while Daniel James always seemed to find half a yard on the Spurs defender.
DF Jan Vertonghen, 6 -- Enjoyed a quieter evening than his counterpart on the opposite flank as the hosts looked to pick out Rashford at every opportunity. Played an important role in crafting his side's equaliser when his cross from the left was flicked on.
MF Moussa Sissoko, 6 -- Provided some vital defensive cover for Aurier against a relentless Rashford. Had to be on his toes and moved swiftly to snuff out the danger with a couple of excellently timed sliding tackles, but his best quality also proved to be his Achilles' heel when he tripped the United man in the area.
MF Harry Winks, 5 -- Picked up an early booking when he clattered James with a ruthless challenge on the byline. Unfortunately, the England midfielder didn't contribute much else as United took control in the middle of the park.
MF Lucas Moura, 5 -- Got the better of Ashley Young as Spurs attacked for the first time, but his cross had no real conviction and was easily cleared. Almost carved out another equaliser for his side when he stole possession from Young and whipped a cross towards Heung-Min Son, but United scrambled the ball clear on an otherwise quiet evening for the Spurs man.
MF Dele Alli, 8 -- The inspired midfielder is back to his best under Mourinho and made it three goals in as many games with a sublime finish at Old Trafford, coolly flicking the ball over Victor Lindelof on the turn before firing past de Gea to drag his side level. An early "Goal of the Month" contender from the 23-year-old.
MF Son Heung-Min, 7 -- The midfielder's persistence was key in the build-up to his side's equaliser just before the break when his dazzling run into the box eventually led to Vertonghen's cross being finished by Alli. Should have made it 2-2 but his effort was blocked by a determined Fred after a clever drop of the shoulder earned him room to shoot.
FW Harry Kane, 4 -- Squandered a rare opportunity to test de Gea when his free-kick from a central area comfortably cleared the crossbar. It was a desperately quiet performance from the captain who saw his speculative effort deflected wide with his only other chance of note.
MF Christian Eriksen, 6 -- Replaced Moura in the 64th minute but made little impact. The Dane saw a cross comfortably charged down by Rashford and lost a battle with Ashley Young when their duel in the corner ended in a goal kick to the home side.
MF Tanguy Ndombele, 6 -- Replaced Winks in the 70th minute after the Spurs man picked up a knock on his ankle. Put in a decent performance and forced a routine save from de Gea with an optimistic drive from outside the area.
Giovani Lo Celso, NR -- Replaced Sissoko in the 86th minute. Didn't have too much time to make a contribution as he saw his fizzed cross comfortably cleared in his only involvement.