The petulance of Mario Balotelli, storming directly down the tunnel to the dressing-room after being substituted early in the second half, again dominated the soap opera headlines that attend the Premier League champions' every move but, at the other end of the field, there was a far more significant development.
Micah Richards, playing for City for the first time in five months in the centre-half position many feel is his best, turned in a performance that suggested he is an obvious replacement for shamed and recently retired England defender John Terry.
Persistent question marks remain over Richards' ability at the very highest level -- as the fact he possesses just 13 caps from a near six-year international career testifies -- but, at the age of barely 24, he is surely worthy of strong consideration.
"I think Micah is a fantastic player and he deserves to be in the national team," said team-mate Pablo Zabaleta. "Micah came back to the team, he was very solid at the back.
"He is young, he is strong and he can give to England what he gives to Manchester City. Terry's not in the international team any more so maybe that is a good chance for him to get into the England team again."
Richards himself declines to discuss his standing with Roy Hodgson and the England squad although, having formed an impenetrable pairing with Joleon Lescott in front of England goalkeeper Joe Hart on Saturday, it is tempting to imagine he can envisage a return to the international fold.
"I was excited to be back out there after being out for so long, me and Joleon haven't played together too many times," said Richards.
"A lot of people don't realise how good he is. He's played for England and he's a top-class centre-back. People always say the foreigners make City's team but we have a good six or seven English lads in the squad.
"When we come in and get our chance we give 100pc."
Richards' return coincided with City's first clean sheet of the season -- although perhaps it was no coincidence -- but the England man was arguably not even the best defender on display.
Full-back Aleksandar Kolarov was a force in defence and scored a magnificent fourth-minute direct free-kick before laying on a second goal for Sergio Aguero, whose 55th-minute introduction so infuriated Balotelli.
As City proved with last season's Carlos Tevez debacle, of course, such distractions matter little to the club, given their colossal financial resources. They have a squad whose depth is unmatched in the Premier League and James Milner's late free-kick completed the rout -- and their 33rd unbeaten home league game.
Far more worrying have been City's defensive performances to date and, for this reason, their display in overwhelming a poor Sunderland team that had somehow remained unbeaten until this point, could prove to be significant.
"In games like this you want to keep it goalless as long as you can, but by conceding early it meant a tough game got even tougher," said Black Cats goalkeeper Simon Mignolet. Many more teams look poised to experience the same problem in the weeks to come. (© Daily Telegraph, London)