When the whistle signalled the fourth goal, the Manchester City players huddled in a celebratory circle of togetherness. The United players were detached and defeated.
"We want five," demanded the City supporters in the south stand. A banner read, 'Not in my lifetime' - a reference to Sir Alex Ferguson's quote about the prospect of City ever finishing above United. A second 5-1 in his lifetime was briefly possible. Joy Division's Love Will Tear Us Apart played at full-time and City fans crowed about tearing United apart.
United have come full circle again. The chasm between them and City 22 points, just as it was at the end of the David Moyes season. Just like in that season, City triumphed 4-1 at the Etihad.
Read more: United player ratings vs City as two players really poor
This time, City were not as merciful against the United AD - after dominance. They have fallen so far it is a minor positive to have participated in a contest with City for a half. Until Riyad Mahrez ended the resistance in the 68th minute it appeared they were still in it.
In truth, the contest ceased with the restart. Normality had been restored by City, doubtless jolted by an animated Pep Guardiola team talk, and they toyed with United, despondent a proactive first-half still ended with them behind.
Bar amateurish defending for the first two goals, United imposed themselves purposefully in the first-half, pressing with intent in an innovative and flexible formation, depriving City of sustained control. Only trouble brewed as soon as City advanced into the final third and at pace against the one-paced pairing of Victor Lindelof and Harry Maguire. City were relentless once they had regrouped.
This was another shellacking in a season laden with them. United have shipped three, four, five and six to City in living memory and there was no danger of a seven-goal haul, at least. Scott McTominay, rattled, offered Joao Cancelo some verbals as he threatened to showboat. The Etihad has now hosted three 4-1s in its 20-year history.
City's winning margin was greater than at Old Trafford in November and their superiority similar in the second-half. There was still a quarter of the match to showcase some exhibition football, Cancelo's scissor-kick volley from outside the area beaten away by David de Gea. The 'ole's started in the 84th minute and the United supporters were inaudible as the City fans resurrected the Poznan.
Predictably, Cristiano Ronaldo's absence was not as significant as Raphael Varane's. United's worst defeats this season - Leicester, Liverpool, City and Watford - have come without Varane, laid low by Covid, and this was another. All four aforementioned sides have put four goals past United, whose defending was reminiscent of the last days of Ole Gunnar Solskjaer.
United have known for two-and-a-half years Maguire and Lindelof's partnership is inadequate for a championship challenge and it is now not necessarily top four standard. Negative test permitting, Varane's return against Tottenham on Saturday would be a positive.
Lindelof, only starting through Varane's absence, was culpable for Kevin de Bruyne's goals, lured to the right for the first and too tentative for the second. Like Aaron Wan-Bissaka, Lindelof is an introvert and they were barely communicative as Jack Grealish, De Bruyne and Phil Foden danced around them.
Rangnick had seemingly prepared for another duel between Aaron Wan-Bissaka and Raheem Sterling, only Guardiola scrapped that undercard by omitting Sterling for Grealish in his only surprise selection. It was not a coincidence City had United on the backfoot down that side and their attack was so lopsided Riyad Mahrez was nigh-on anonymous on the right until late in the first-half. He scored twice in the second.
Wan-Bissaka's second-half started as badly the first ended, with him meekly playing in Bernardo Silva before he was sent thudding down to earth by Foden. Diogo Dalot's sudden withdrawal from the side remains as dubious as Edinson Cavani's commitment and a frustrated Fred let rip at Wan-Bissaka during City's procession period.
The United supporters could be heard serenading the present Roy Keane, who played on at Elland Road after rupturing his anterior cruciate ligament to prevent his teammates from playing with 10 men. United now have Cavani, unavailable whenever the club claims he is available. Cavani has now missed 23 out of 38 this season.
The United players who disembarked the team coach at Eastlands were lacking in quality, if not commitment. Anthony Elanga merited a first derby start but it will be remembered for his loose pass that City clinically seized on to regain their lead. Elanga was hooked just past the hour.
The relocation of Pogba to centre forward was rewarded with his curved pass for Sancho, who used Kyle Walker as a decoy, dummied Rodri and curled the ball into the corner. His celebration screamed, 'look at what you could have had' as he edged nearer the baying blues.
Two United supporters' cover in the City section was broken as they celebrated. They were repeatedly told to 'f--k off' and dubbed a 'red b-----d' by a schoolboy barely out of primary school. An old boy with a woolly hat on bearing the old City badge enquired, "Do you want some?" without offering any. They were soon sniping again when De Bruyne breached United for the second time.
It was friendlier on the touchliune as substitutes Sterling, Marcus Rashford and Jesse Lingard exchanged pleasantries. Rashford offered the Ukrainian Oleksandr Zinchenko some encouraging words and an embrace. Rashford also appeared charitable when played onside, passing up a shooting opportunity.
City didn't and completed the circle.
Sign up to our United newsletter so you never miss an update from Old Trafford this season.
Catch up on all the latest Reds headlines in our United section