Sergio Aguero has been the bane of Manchester United since the moment he arrived in the Premier League. The move to City in itself was a blow for the Red Devils—who had at one stage looked to sign the Argentinian from Atletico Madrid themselves before City swooped in to snap up the striker.
Next, in what had already been an outstanding debut season, Sergio went on to score a 94th-minute winner to bring the title back to the blue half of Manchester for the first time in over half a century.
Last night he struck a blow to the hearts of United fans again, coming off the bench and scoring the winning goal in the Manchester derby.
The victory left City 12 points behind United with just seven games of the season left to play. An unassailable lead? In theory yes, but with games against Arsenal and Chelsea still to come for Fergie's men, it is no longer the dead cert it seemed to be before kickoff.
But does City's victory genuinely give them an outside shout at back-to-back championships? And aside from this season, what does the performance say about the two clubs rivalry in the long term?
In regards to this year's title, things shouldn't be too heavily affected. In fact, if United can pick up all three points against struggling Stoke City on Sunday and pick up at least a point against West Ham the following week, then the title could be all but secured for the tablecloth army.
The matches are running out for the Sky Blues. if this fixture had come a few weeks ago, then we could have been looking at another amazing comeback from the champions, but with less then sixth of the league season remaining you would be hard pressed to see United drop 12 points out of a possible 21.
That is, of course, assuming that City also win every game from now until the end of the season—not entirely unlikely, but with a trip to White Hart Lane to face Spurs still remaining that will be a tall ask.
No, last nights victory for Roberto's Mancini's men more than likely wont change anything in regards to this year's campaign; United should be able to hold out for yet another Premier League crown.
However, the game did once again emphasise United's inability to cope in the centre of midfield with the likes of City, Chelsea and other top European sides.
This has been an area of weakness for far too long now. In fact—in regards to the centre of the midfield—we are approaching four or five years since United were competing with the top clubs in world football.
Weirdly the signing of Robin van Persie was actually a move in a positive direction. His addition to the United strike force resulted in Wayne Rooney being dropped into a deeper role just in front of the midfield.
However, with the 39-year-old Ryan Giggs being given more and more responsibility, United fan's must be concerned that Sir Alex is relying so heavily on a man who is literally a year away from retirement.
With the exception of Michael Carrick, the United midfield was completely out-matched by the talent on show in both the recent City and Chelsea games. That has to change.
Last season Sir Alex signed Shinji Kagawa in an attempt to fill this void, and—as much as it pains me to say—the man from Japan just hasn't cut the mustard yet.
Tom Cleverley was another bright talent that this reporter once touted for greatness, but with world-class performances followed by frustratingly mediocre outings, his inconsistency is something that deprives him of reaching the potential that Sir Alex expects of the 23-year-old.
Manchester United have to sign a solid, proven and world-renown central midfielder over the summer. There are several good options across the globe right now who are definitely sign-able if you're Manchester United. Kevin Strootman, Mario Goetze, Luka Modric, Gareth Bale and even Barcelona star Cesc Fabregas (who is desperately struggling to fit in on the pitch despite having such strong connections at Barca) are all players who would be accessible for the right price.
The 2-1 defeat is not a disaster for United, but it should act as a disappointing wake up call for Fergie with the summer window just on the horizon.