3 things we learned as Rashford delivers Manchester derby victory for United

United was victorious at City in the 171st installment of the Manchester derby, blowing the race for Champions League football wide open as the top tier enters the final run-in.

The home side's lack of battle was displayed once again, as Marcus Rashford stripped Martin Demichelis of his dignity in the 16th minute before confidently finishing beyond Joe Hart. That was all the Red Devils needed to secure all three points in a closely fought meeting.

Here are three takeaways from United's 1-0 triumph at the Etihad Stadium:

Rashford justifies central role

Rashford is a real shining light of United's campaign. He has a fearlessness that was lacking when Louis van Gaal was widely hounded for a limp style of football earlier in the season.

He slid the winner beyond Hart as if he's been doing it for years, but the talented 18-year-old only made his first appearance in professional football last month.

He scored two goals in his full debut against FC Midtjylland, two in his Premier League debut against Arsenal, and one in his bow in the derby. England's stacked legion of forwards and Rashford's Under-20 pick suggest he'll have his chance for full international honours, but on this introduction he'll take some usurping when he gets there - his club exploits have already shunted £58-million Anthony Martial out wide.

Demichelis is an unmitigated disaster

You can't talk about the tormentor without discussing the tormented.

En route to opening the scoring, Rashford jinked past Demichelis with ease, leaving the veteran toppling like the statue of a fallen despot. It isn't Demichelis' insurmountable power that has him in the starting XI, though; rather, it's the repeated spate of injuries and the crippling decision from Manuel Pellegrini to keep him around.

Demichelis wasn't done at getting shown up by a teenager. The 35-year-old should've conceded a penalty after bumping Rashford over as the first stanza was nearing its end, and early in the second half he played a shocking back pass that required Joe Hart to slide in to clear ahead of Martial. The England No. 1 suffered an injury in doing so, requiring a stretcher to leave the fray.

Demichelis was hauled off on 53 minutes, with midfield Fernandinho slotting into the back four.

Again and again Demichelis' lack of mobility is shown up by his Premier League contemporaries, leaving City fans scratching their heads at the fact that Jason Denayer is some 1,685 miles away in Istanbul. True, the Belgian's season-long loan at Galatasaray has been shown up by a busy treatment room, but you suspect the 20-year-old, who has a similar cultured and composed style to his compatriot Vincent Kompany, would've fared much better than Nicolas Otamendi and Eliaquim Mangala, too.

Demichelis' shortcomings were clear long ago: He isn't of that required quality - far from it - and should've never been offered that contract extension last March.

Where will these teams end up?

There are contrasting stories in Manchester. City started the season in storming form, but has since stumbled with its old guard looking languid and disinterested. United, on the other hand, was roundly panned for going against its risky attacking traditions, but has reversed its fortunes through youthful legs.

Incredibly, City is running close to not having Champions League football to offer incoming gaffer Pep Guardiola next season, and the lack of tempo and slumped shoulders put a lot of emphasis on the impending returns to fitness of Fabian Delph, Samir Nasri, and Kevin De Bruyne.

Whenever United appears to hit a forward cycle, a branch is often thrust into the spokes. There aren't many greater boosts than clinching an away win in the derby, though. West Ham United lurks in close quarters, too, but City is still the favourite with the British bookmakers.