Marcus Rashford overtakes George Best as Manchester United's youngest European goalscorer in FC Midtjylland Europa League win
Marcus Rashford was the unlikely hero in Manchester United's do-or-die clash with FC Midtjylland, marking an unexpected debut with a dream brace that saw Louis van Gaal's men through a tricky Europa League tie.
Rashford - at the age of 18 years and 117 days - overtook George Best as Manchester United's youngest ever goalscorer in Europe.
A terrible string of injuries has seen United forced to rely on youth products, although the 18-year-old striker was so far down the pecking order his name did not even appear on the back of the matchday programme.
Rashford is likely to be the cover star next time, though, having been thrust into the spotlight following Anthony Martial's warm-up injury and netting twice as United overcame a first-leg defeat and first-half Midtjylland goal to win 5-1 on the night and 6-3 on aggregate.
It was a dream end to an evening that looked to be going horribly wrong when Pione Sisto all-too-easily carved open United's makeshift defence to put the Danish champions ahead at Old Trafford.
Nikolay Bodurov, on loan from Fulham, turned a Memphis Depay cross into his own goal shortly afterwards, but nerves grew as Morgan Schneiderlin hit the woodwork and then Juan Mata saw a penalty saved.
They need not have worried, though, as Rashford came to the rescue, turning home crosses from Mata and Guillermo Varela to put United in the driving seat.
Ander Herrera's penalty and a Depay strike either side of Andre Romer's red card added extra gloss to the scoreline as they progressed to the last 16.
The result eases the pressure on Van Gaal, who called for his team to be hungry and, rather amusingly, "horny" in the build-up to a match which ended a run of four games on the road.
Martial's warm-up blow took the number of injured first-team players to 13 and led to Rashford making his debut alongside 19-year-old Joe Riley, who made his first start in a defence that saw Michael Carrick drop back to partner Daley Blind.
The makeshift backline was not tested early on as the hosts pressed, albeit without seriously threatening until a Rashford snapshot forced goalkeeper Mikkel Andersen to tip around the post.
Midtjylland's organised defence was frustrating the hosts, who were caught by a 28th-minute sucker punch
Sisto capitalised on the home side's hastily-assembled backline during a rare voyage forwards, turning Blind with ease and skipping past Carrick before firing a low, right-footed strike past Sergio Romero.
It was a strike against the run of play and a setback United responded to with defiance.
Depay had been a nuisance from the outset and finally punished the visitors, sending in a fizzing cross that Bodurov turned past his own goalkeeper.
Schneiderlin went close with an overhead kick and hit the woodwork in-between a long-range Depay strike as resurgent United looked to take the lead - something they appeared set to do when Herrera was taken down by Romer.
Referee Istvan Vad pointed to the spot and Mata stepped up, only for Andersen saving the penalty down to his right.
It was a missed opportunity United looked determined to atone for after half-time, with Schneiderlin and Herrera, in particular, wasting good chances.
The hosts launched attack after attack and the breakthrough eventually arrived in the 64th minute. Mata impressively cut back at the far post and Rashford capitalised, slotting home and wheeling off in celebration.
United fans expected to have another chance of a penalty shortly afterwards as Jesse Lingard went down, only for the winger to receive a booking for supposedly taking a tumble.
However, they were not to be frustrated for long as Rashford's dream night continued, turning home after Varela clipped in a ball from the right.
It was a blow Midtjylland were unable to recover from and matters got worse in the dying stages, with Herrera turning home from the spot after Kian Hansen handled a Depay shot.
Romer was then sent off for a second yellow card, before Depay took aim from the edge of the box to make it five.