The Etihad Stadium is adorned by a banner celebrating an extraordinary passage of added time. Reading "93.20", it commemorates the minute and second in May when Sergio Aguero denied Manchester United their 20th league title. Should Sir Alex Ferguson's team regain their league at their neighbours' expense, Old Trafford may have its equivalent: "91.43".
It was then that Robin van Persie bent in a free kick and Samir Nasri, in a dereliction of duty, waved a leg and only succeeded in applying a telling deflection. The ball nestled in the far corner of Joe Hart's net. It was Manchester City 2 Manchester United 3. The game Roberto Mancini said City mustn't lose was lost. The result Ferguson had claimed would be one of his greatest victories was secured. "Today was a special one," the Scot said. "You couldn't take your eyes off it. It was so engrossing." Indeed, the sort of drama this derby delivers in abundance was supplied and then garnished.
Thanks to the moronic minority in the City support, Rio Ferdinand was hit by something thrown from the stands. Ferguson and Carlos Tevez, allies turned enemies, traded words angrily after the Argentine's hack at Phil Jones. And, when referee Martin Atkinson's whistle went for the final time, the balance of power in Manchester had shifted from blue to red.
Perhaps it did that August day when Van Persie picked Old Trafford as his preferred destination. One waft of his left foot was a microcosm of his impact. The talent and talisman has supplied 11 Premier League goals. They have been worth 16 points. The eloquent Dutchman is the master of having the final word.
He changed the complexion of the title race; perhaps even of Mancini's reign at City. The proud, unbeaten run, dating back almost two years in home league games, was ended at 37 games. The last defeated start to the season had disappeared and United's lead at the division's summit was extended to six points.
An eight-point deficit was retrieved last season. "I am sure we can win the double this year," said a bullish Mancini. But out of Europe, they are outsiders in England now. The recriminations began quickly. City only had three players in the injury-time wall. "Two and a half," said Mancini, in a veiled criticism of Nasri. For reasons that eluded the Italian, Tevez, who should have been the fourth, had already detached himself.
Another striker came in for more criticism. City's new father reverted to being their enfant terrible. "Mario [Balotelli] cannot continue to throw his quality out of the window," added Mancini. A second phrase was almost identical to the words he spoke, 13 months ago, when Balotelli was the architect of City's 6-1 win at Old Trafford. "I love Mario like a guy and also like a player," he said.
But United's strikers were the more reliable. Both could have lined up in City colours. Wayne Rooney was linked when, in October 2010, he submitted a transfer request at Old Trafford. Van Persie was a summer target.
"Van Persie scores against every team," added Mancini, suggesting the Dutchman had not singled out his suitors for special treatment. Rooney, however, reserves his best for City.
A double took his derby tally to 10, eclipsing Bobby Charlton to make him United's most prolific player in all-Mancunian meetings. Both came from clinical counter-attacks, Rooney angling a shot into the corner of Hart's net after Van Persie and Ashley Young had combined and then converting Rafael da Silva's cross. On both occasions, too, he was operating as a classic No.10, finding space between the lines and exposing City's lack of a specialist destroyer at the base of the midfield.
So, aping their neighbours, they had to mount a comeback. They were aided by errant officiating. After Van Persie struck the post, Young despatched the rebound and was wrongly deemed offside. "It's a funny game, football," said Ferguson, channelling Jimmy Greaves and adopting a rather more philosophical approach than he would if it had cost United.
Instead, City broke at speed. David de Gea made a brilliant double save to deny Tevez and David Silva but could not stop Yaya Toure from halving the deficit. With four minutes to go Pablo Zabaleta drilled City level. "They came back and were fighting like hell with their three strikers," Ferguson added. Having claimed United's title, City were aiming to take their crown as comeback kings.
Except, of course, for Van Persie's intervention, bringing a wonderful second half of quick counter-attacking to an improbable, yet somehow predictable conclusion. "We won the league with the last touch of the ball last year," remembered Mancini, harking back to Aguero's heroics against QPR. "This can happen."
It can in these dramatic derbies. It was a typically Mancunian ending to an affair witnessed by two Hollywood luminaries. Tom Cruise's presence generated mentions of Mission Impossible and Top Gun even before the ex-Gunner made United Manchester's top team. But the appearance of Robert Duvall, film's most famous consigliere, was a reminder of Ferguson's status as the Godfather of management. And after the unprecedented embarrassment of the 6-1, this was revenge for Don Ferguson, head of the United family.
MAN OF THE MATCH: Wayne Rooney - Mediocre against Cluj but magnificent against City. Rooney is perfectly suited to high-paced games such as these where he is afforded space to operate in. However, it was somewhat typical of his season that he was still overshadowed by Van Persie.
MANCHESTER UNITED VERDICT: On the back foot for 15 minutes, they then scored twice and prospered on the counter-attack. They had to weather a City onslaught in the second half, when De Gea impressed and substitute Chris Smalling made a superb last-ditch challenge but were ultimately worthy winners. It helped that the ever-excellent Antonio Valencia was fit again. There is no more devastating right-sided partnership in the Premier League than United's two jet-heeled South Americans and having been removed after half an hour at Reading eight days earlier, Rafael marked the same stage of the game by supplying Rooney for United's second goal.
MANCHESTER CITY VERDICT: Second-half specialists rallied after the break, galvanised by the arrival of Tevez and an improvement from Silva. Yet Nasri was a disappointment again and Mancini is likely to be criticised for selecting Balotelli, even if he had some grounds to choose a past tormentor of United. A worry is that captain Vincent Kompany limped off with a groin injury.