Manchester City's lack of spark against United a cause for concern
Pellegrini's champs look like a shadow of the side that tore up the premiership last season
The sense of superiority grows. Six out of Manchester City's last seven Premier League derbies have now brought victories and there are four in a row for the first time since 1970 - a year when no one denied which was the best team in town.
Yet there is something missing - the swagger and the style we've come to know in City.
On this weekend last year they were tearing though Norwich City, 7-0 at the Etihad, four days after beating Newcastle United in the League Cup, with five-goal demolitions of CSKA Moscow and a tally of six against Tottenham Hotspur about to follow on home soil. Memories now.
Doubts about the team who have just run out winners in a Manchester derby will always be open to challenge but not even three unjustly denied penalties can disguise that the narrative of this football match was scrambled.
The look on the City players' faces when the final whistle blew spoke only of relief. They knew. The City side that won last season's Premier League would have torn asunder a defensive unit as unfit for purpose as United's. This one didn't.
They were the better team, for all Wayne Rooney's claims to the contrary. Marco Rojo versus Sergio Aguero was a battle which had given those United fans not blinded by personal loyalty cause to fear in recent days and the angst didn't prove unfounded.
Aguero will crucify any defender who grants him a first touch and a yard. Rojo indulged him with that three times, early in the first half.
There was also the moment of sublimity which rather got lost in the subsequent mist of controversy: the three-touch triangular movement which forced David de Gea to save when Jesus Navas bore down on him.
Manuel Pellegrini will say there would have been much more of this had David Silva been on the field. The little Spaniard against the 10 men would have been some sight to behold from City's perspective.
But none of that can disguise the way that City lost their direction in their 51 minutes of numerical advantage. There are reasons why Chelsea's six-point lead doesn't seem to tell the full story of the Premier League leaders' superiority and one of those is City's defence. We saw why once again. United were winning aerial battles from the game's opening minutes when Robin van Persie was leaping to head down Angel di Maria's chipped ball for Adnan Januzaj, who shot wide as Vincent Kompany made a vain attempt to dive in. At the other end of the game, Kompany was on the wrong side of Marouane Fellaini as he missed the header which should have put United level.
But there was something more fundamental to City's malaise than that. Draw a symmetry between this game and the Manchester derby of almost exactly three years ago - the 6-1 win at old Trafford on October 23, 2011 which left Sir Alex Ferguson reflecting on wanting to put his head in the oven - and you see the diminution of City in plain view.
United had a central defender sent off around the half-time mark on that day, too: Jonny Evans, only 10 minutes deeper into the game than Chris Smalling's departure here.
And Roberto Mancini's City simply went berserk. They were 1-0 up when Evans left the field and had added two more by the 70- minute mark.
Here, their two lines of four - deep-lying from the start; always allowing United 15 yards of territory to advance into - stayed much the same. The lack of the killer touch was down to personnel. James Milner was replaced by an insipid Samir Nasri and the side, frankly, disintegrated.
The lack of the killer touch was also down to the manager. The absence of an alternative plan applies just as much to an ascendant position as to a losing one. Smalling's departure created the chance for City to up the tempo, make the pitch bigger and drive home the advantage. It didn't happen. Aguero's hostile reaction to being substituted told the story of an afternoon that was just not working out.
This side don't seem to have the same hunger this season as last and perhaps it is winning the Premier League title which makes it so. To clinch that prize takes ability. To want to clinch it year after year, as United have done, takes a deeper quality which City also lacked two years ago.
It also requires a manager capable of putting a little of the fear of God into a team. Joe Hart, who was called upon to save his side late on, observed last week that not all managers need to "smash up" the dressing room. Well, it feels like some damaged furniture would do City good, glad though they are that the internal strife of the Mancini era is in the past.
The consequences of not smashing this game up could be substantial.
Defeat condemns United to their worst start to a season since 1986 and this was City's opportunity to drive home such ignominy and drive the old enemy down into the mire. Instead, when the dust settles today, United can allow themselves to look around the place and feel like winners. They will thank City for that.