United now a team perfectly in tune with their manager's plans
Manchester Utd 4 Manchester City 2
Manchester United now look a team totally in tune with Louis van Gaal's demands, playing with shape, belief and verve. By contrast, Manchester City look a side drifting apart from Manuel Pellegrini, surrendering their title meekly, being blown away by hungrier neighbours here and with supposed leaders such as Yaya Toure going missing when needed most.
For the opening 10 minutes, during which Sergio Aguero ended a barren spell of 564 minutes without a goal, City were terrific. They attacked busily, seeming to understand the passion-play nature of derby day, but it proved to be a false dawn rather than a Blue Moon rising. United responded superbly, ripping the champions apart, scoring through Ashley Young, Marouane Fellaini, Juan Mata and Chris Smalling before Aguero's 100th goal for City proved an irrelevant postscript rather than a landmark to be celebrated.
Old Trafford shook with noise, reverberating with a swaggering confidence in their revival under Van Gaal. Two of David Moyes's recruits, Fellaini and Mata, are focusing their abilities more successfully and consistently under Van Gaal, whose influence is being seen all over the team in strong individual displays. Young has rarely played better, brimming with pace and ambition, delivering another message to Roy Hodgson in the stands.
Michael Carrick was organiser-in-chief, intercepting and recirculating the ball, dropping back into the back four to keep the shape and instructing Chris Smalling and Phil Jones like an attentive tutor. In front of Carrick, Ander Herrera was similarly excellent, always positive, always looking to dart forward with the ball, or pick out team-mates. Fellaini was a one-man threshing machine, cutting a swathe through enemy territory.
Van Gaal appears to have fostered good partnerships all over, strengthening United further. Young's understanding with Daley Blind on the left continues to impress. Herrera and Mata clearly enjoy working their little passing moves upfield. Smalling and Jones appear a more solid axis, particularly with Carrick close by. Wayne Rooney and Fellaini look a well-balanced, split attack.
There is strength in depth. If the expectation is that Radamel Falcao will not be kept on, Angel di Maria's future is less clear; a fabulous attacking force, he lacks Young's willingness to track back, in keeping with Van Gaal's requirements. Even Mata has (largely) responded to the coach's commands. Thrillingly for the Stretford End, Van Gaal appreciates the club's tradition of operating with width. Even his favourite Chinese restaurant in Manchester is called Wings.
If the title race looks over following Chelsea's win at Queens Park Rangers, the battle for second has become tense with Van Gaal's side a point behind second-placed Arsenal. A run-in involving Chelsea, Everton, West Bromwich Albion, Crystal Palace, Arsenal and Hull City contains some significant problems but United are clearly on the march under Van Gaal.
To talk of a shift in power locally is arguably precipitous as City had won the previous four meetings against United, and have lifted the Premier League trophy twice in the past three years, but they will need to recover quickly. Their supporters sang to the final whistle, and beyond, but the players let them down badly.
The question was raised again over whether they are playing for Pellegrini.
Their discipline is being brought into question; even David Silva was cautioned for a bad challenge while their captain, Vincent Kompany, should have been dismissed for a studs-raised lunge at Blind.
City's recruits are being increasingly scrutinised, not least Eliaquim Mangala, signed for £42million, yet needs to work on the art of marking and learn how offside traps really work. Pellegrini deserves the ongoing inquest but so do the power-brokers who fashioned this squad, Ferran Soriano and Txiki Begiristain. City need a clear-out, injecting quality, youth and desire.
Pellegrini also has to share culpability for a season deflating like a slow puncture on an expensive car, leaving it with only a hard shoulder to cry on. On New Year's Day, the champions shared top spot with Chelsea after 20 games and 46 points, after a winter harvest of 25 points from 27.
Since starting 2015 with victory over Sunderland, City have taken only 15 points from 36, slipping to fourth. They face Southampton on the final day of the season and must collect points quickly to ensure that game does not become a play-off for the last Champions League place.
Yet they started so brightly here. Those tuning in via Sky were treated to a classy tribute to Richie Benaud from the commentator, Martin Tyler, who declared "the prospects for play: marvellous". Nice touch, prescient too.
This was one of those breathless Premier League dramas that captivates audiences around the world.
For 10 minutes, City shone. Pellegrini had been hoping for a reaction from his players, having claimed they had chucked their season "into the garbage". For 10 minutes, they looked a team. Jesus Navas broke through but David de Gea denied him. Carrick did well to intercept a Toure shot.
Then came the goal after eight minutes: James Milner angled a pass down the inside-left channel to Silva, who stroked the ball across for Aguero.
United hit back within six minutes. Jones struck a back-pass dangerously short, especially with Navas lurking, but De Gea read the situation well, running out and clearing long to the left. United's swift transition caught the visitors out. Fellaini and Pablo Zabaleta became entangled challenging for the ball, which fell kindly to Herrera, who drilled in a cross with his left foot. Gael Clichy tracked Young's run to the near post and looked to have averted the danger but the United winger was quickest to the loose ball, slamming it into the net.
United attacked again, Young a force again. Having combined well with Blind after 27 minutes, Young spotted Fellaini at the far post and lifted in a perfect cross. Clichy would have needed a stepladder to challenge Fellaini, even if the left-back had been alive to the Belgian's presence. Fellaini's header was too good for Joe Hart.
City lost their composure. Silva flattened Mata. Kompany flew in on Blind, his right boot catching the Dutchman's left ankle. Mark Clattenburg took his time, even consulting with his assistant Jake Collin before surprisingly deeming the offence worthy only of yellow.
Kompany failed to reappear for the second half. He had been clutching his right thigh as he launched himself at Blind, and the damage was done.
Mangala came on and more damage was inflicted. Taking Blind's pass and turning Mangala after 67 minutes, Rooney threaded the pass through to Mata, who placed the ball between Hart's legs and in.
Pellegrini stepped into the technical area to survey the damage from closer quarters. "You're getting sacked in the morning,'' was the instant chant from the Stretford End.
Six minutes later it got worse for Pellegrini. Young swept in a free-kick from the left, Mangala played most of the Stretford End onside, let alone Smalling, who headed home. Aguero pulled a late goal back after Zabaleta pulled the ball back but the damage was done. (© Daily Telegraph, London)