Only after the fourth goal had been scored, only after this derby demolition had been completed, did Louis van Gaal turn to the most expensive player in English football and the player who commands the highest wages. Angel di Maria and Radamel Falcao were little more than fresh legs here on Sunday, and any success Van Gaal has enjoyed in his first season at Old Trafford needs to be measured against the difficulties two phenomenally talented players have endured. But it also a measure of the qualities the Dutchman possesses that players with only a fraction of their ability are not just keeping them out of the side, but are performing as well as this. Angel di Maria and Radamel Falcao were left on the bench by Louis van Gaal on Sunday . Argentine £60m man Di Maria came on for Juan Mata in the 81st minute at Old Trafford . Falcao replaced Belgian Marouane Fellaini with seven minutes to play in the win over Manchester City . A sixth successive Premier League victory that cements United in third place owes much to the revival of Ashley Young, Marouane Fellaini and Juan Mata and the progress being made by Chris Smalling and Phil Jones. David Moyes once said Smalling and Jones were good enough to become England’s central defensive pairing and Roy Hodgson, a spectator here on Sunday, is sure to be encouraged by their rate of development. In Young, Fellaini and Mata the transformation has been most startling, however, and credit has to go to Van Gaal for the way he has managed three players who were so central to the downfall of Moyes 12 months ago. In fairness to Fellaini, and indeed Moyes, the Belgian just needed time to make the transition from Everton to United. In fairness to Mata, he probably needed time, too, after being ejected from Chelsea by Jose Mourinho. Ashley Young celebrates after bringing Manchester United level having earlier trailed . But Young is a triumph for the style of leadership Van Gaal has long been recognised for: his ability to work with players on a personal basis as well as part of a collective. Even Van Gaal’s critics recognise the skills that also made him a fine schoolteacher when he was supplementing his income as a poorly paid player in Holland with a career in education. He is clearly very good at restoring confidence and inspiring an individual, with Young finally looking like the player Martin O’Neill used to admire so much. Young, one of five Englishmen in United’s outfield 10, was the outstanding player in this hugely entertaining contest, scoring the equaliser that quickly cancelled out Sergio Aguero’s opener, as well as providing the assists for Fellaini and Smalling, but more to the point, responding most effectively to what, presumably, were his manager’s instructions. Fellaini headed in at the far post to give Manchester United the lead and continue his fine recent form . Mata slots under Joe Hart to extend Manchester United's lead to 3-1 early in the second half . Van Gaal would have seen how vulnerable City were to the aerial threat posed by Crystal Palace at Selhurst Park on Monday and it was Young who delivered the crosses that enabled United’s tallest players to punish them again, on both occasions with headers. Exactly why the issue had not been addressed by Manuel Pellegrini is anybody’s guess. But if this game highlighted the skills of Van Gaal, it also illustrated where City’s beleaguered manager has fallen short this season. While United are in the ascendancy, Pellegrini has overseen a period of decline for a stuttering City side. While United are now celebrating the renaissance of players like Young, Pellegrini faces the question of what on earth has happened to a side who were so superior to United a year ago. Chris Smalling headed in a free-kick to score Manchester United's fourth goal in the derby . England manager Roy Hodgson watched the Manchester derby from the stands at Old Trafford . 5 - Games lost by City in 2015, one more than the whole of 2014. 13 - City's position in the Premier League form table after losing four and winning two of his last six. 4 - The first time since losing 4-3 to United in 2009 that City have conceded four in the league. 9 - City have nine points fewer than they did at this stage last season. 70.8 - City's pass completion rate percentage at Old Trafford was their worst of the season. It was a 3-0 win at Old Trafford that effectively finished Moyes at United, with the eventual champions moving 15 points clear of their neighbours that day with two games to spare. But this game was a microcosm of City’s season: a decent start, marked by that first Aguero goal, and then a period of steady, draining decline. Since the turn of the year City have collected just 18 points from 13 games. Compare that to United, who have taken 29 from the same number of matches. Pellegrini was honest enough to admit that they have thrown away their title defence with the ‘garbage’ but the real garbage is on the pitch, in the form of some truly inept performances. Not least away from home. If Pellegrini had a desire to ‘continue being noisy’ and extend a period of dominance over their neighbours to a fifth league meeting, the evidence on Sunday would suggest it was not shared by his players. They were a poor imitation of the side that so impressed here last year. Nothing like the champions of England. Louis van Gaal shakes hands with his opposite number Manuel Pellegrini after the final whistle . Manchester United boss Van Gaal thanked supporters for their patience after Sunday's victory . Manchester City boss Pellegrini has come under increasing pressure after a dismal second half of the season . Compared to Chelsea, United are some way short of the best in England too and both clubs will need to invest heavily again this summer to close that gap. But this morning United and City appear to be travelling in opposite directions, one on the rise and the other entering another period of upheaval. Vincent Kompany blames financial fair play but overlooks the fact that Pellegrini has actually spent more than £75million since last summer. Just as he ignores that the problem is closer to home; that he is chief among players operating on restricted power. At Old Trafford the drop in standards at City was obvious to all, and probably explained why the atmosphere was electric. United’s supporters are enjoying seeing City suffer as much as they are now beginning to appreciate the leadership of Van Gaal. His management has taken on an almost magical quality. Judging by the fact that he can keep his two most expensive players on the bench for 80-odd minutes and nobody even notices.
Manchester United beat Manchester City 4-2 at Old Trafford . Win moved United four points clear of City in third place in the table . Louis van Gaal has left Angel di Maria and Radamel Falcao on bench . Ashley Young, Juan Mata and Marouane Fellaini have all been revived . Chris Smalling and Phil Jones are showing progress at the back .