Several generations have passed since this Mancunian duel was played against a backdrop of such mutual struggle, with both sides searching for form in chase of their respective goals.
The incredibly nervy opening stages epitomised the struggles facing Pep Guardiola and Ruben Amorim respectively, with neither outfit willing to step forward and assert themselves on the game.
Mason Mount’s withdrawal through injury was just about the only noteworthy moment of the first 20 minutes, after which a shot finally arrived when Phil Foden dragged a volley wide of the target.
With frustration growing around the Etihad, the visitors grew into the game, but as against Arsenal at the start of December, a crushing lack of conviction in the final third proved their undoing.
Manuel Ugarte was the man to have United’s first effort at goal when he blazed over on the half-hour, but not long afterwards it was City wheeling off in celebration.
A familiar foe failed the Red Devils again, as a short corner routine saw Kevin De Bruyne’s cross deflect perfectly onto the onrushing, unmarked Josko Gvardiol to head home the eighth goal United have conceded from corners this season.
It’s the second time Amorim’s United side have failed to register a shot on target before half-time, but the vocal travelling contingent weren’t treated to much better once play resumed.
Amad Diallo - as has often been the case in recent weeks - fought a lone hand in terms of attacking intent, with his header from a Bruno Fernandes cross tipped around the post by City goalkeeper Ederson.
The visitors’ gameplan to wait for a clear opening so nearly came to fruition in the 74th minute when Rasmus Hojlund slotted Bruno Fernandes through on goal, but the United captain fluffed his lines, sending his chip over the onrushing Ederson wide of the target.
The Dane had previously been left aggrieved at not earning a penalty having been felled by Ruben Dias in the box, but Amad would not be denied in the closing stages.
Having pounced on an awful backpass from Matheus Nunes, the Ivorian was wiped out by the City midfielder, presenting Fernandes another chance to rescue a point for the visitors.
This time, Fernandes made no mistake as he sent Ederson the wrong way before United silenced the Etihad by completing the most unlikely of comebacks.
Lisandro Martinez’s brilliant ball in behind was perfectly weighted for Amad, whose touch took him around Ederson before applying the finishing touch, sparking bedlam in the away end.
That knocked the stuffing out of City, who succumbed to just a second defeat in the last league meetings against United to fall some nine points off the title pace.