There’s a scene in Forrest Gump where the film’s hero reacquaints himself with his old army Lieutenant Dan by throwing himself off his shrimp boat, leaving the vessel to weave around the estuary by itself.
Arsenal’s defence — with Shkodran Mustafi starring as a kind of permanent tribute to Lieutenant Dan — spent the entire afternoon careering around the Etihad a pace or two behind City’s quickstep.
“That’s my boat,” Forrest explains as the fast-steaming but crewless ship takes out the quay behind them. Likewise, “that’s my defence” could have been Unai Emery’s first comment on reaching the safety of the media area at the Etihad.
Little was he to know that Mustafi has previous in this fixture, his crepe-paper challenge on Aguero in last season’s League Cup final leading directly to the first goal at Wembley.
Indeed the Spaniard, famed for his artistic work The Many Faces of Unai Emery, had already showcased a number of trademark grimaces and looks of inflated surprise by the time Sergio Aguero’s worm-high header put City in front on 48 seconds.
A tardy goal compared with the effort at Newcastle in midweek, but nevertheless City were stepping on the pedals with alacrity and hoping not to hit the brakes by mistake, as they had done on Tyneside.
In a game of close-in goals, Arsenal’s equaliser was another header at ankle height, this time bobbled in by Laurent Koscielny after City’s backline had gone to sleep.
Pep Guardiola, wearing a grey shawl, looked miffed. A water bottle flew, as did some choice Catalan phrases. City’s line up now came under scrutiny.
The team sheet had offered one of those infrequent pleasures of getting halfway through it and having to start again in order to work out what was the general idea.
Arsenal were being asked to attack a back three, heavily bolstered by Fernandinho and Ilkay Gundogan. It was immaterial, however, as the Gunners soon resigned themselves to being outpassed by the triumvirate of David Silva, Raheem Sterling, and a resurgent Kevin de Bruyne.
Aguero’s second, knocked in after an unerring pass on the volley from Sterling across the face of the goal, was a classic City routine.
It was nearly half time. Arsenal could have been forgiven for wanting to regroup, watch their manager pull some tea-break faces, and maybe get some ideas together for a second-half comeback.
Their plan, it soon became evident, was to go about City by not having shots at goal. Those brilliant minds who collate these sorts of things told us this was the first Arsenal half since 2015 without a goal attempt.
More importantly for City, it was the kind of passive-as-porridge response that will help hoist confidence again, as Liverpool’s latest “big lead” turns into mist.
Arsenal, for whom Thierry Henry and Dennis Bergkamp once had so many goal attempts at City’s ground that the home crowd offered them a standing ovation as they left the pitch, were a pale shadow for former selves.
It seems decades since those days of delicious passing ceased. City are the league’s passing team now, an invisible thread connecting players and ball together.
Aguero’s hat-trick goal needed no such guidance, however, skidding gently in off a combination of buttock, hip, and elbow.
It was a scruffy way to hit a monumental high watermark: The 11th time in 12 years the Cannonball Kid from Independiente has gone past the 20-goal margin in a season.
By this stage, Arsenal had ceased to provide proper resistance with ex-City starlet Denis Suarez yet another inclusion to a side that needed bite and thrust, not yet more pretty technicians.
Emery grimaced one last time as Guardiola, still his master after 12 head-to-head outings, closed off the game.
The Arsenal man was left to rue what might have been had his team summoned some inner strength. But that particular boat had already sailed.