They say you can't buy team spirit but City certainly played with character and commitment in beating their neighbours at Wembley. They are still pretty dire to watch at the best of times, but their defence against United's, with no Tevez and no Rooney, meant that the first goal was always likely to be decisive.
It came early in the second half when Michael Carrick, just when it seemed he had left behind his poor form, ballsed up on the edge of the box, presenting the ball to Yaya Toure. The Ivorian is, they say, the most overpaid of players in this overpaid league, but he is also one of the most underrated. In a match lacking in midfield class, he stood out in general, but particularly here as he powered past a flat-footed Vidic and slipped the ball through the legs of Van der Sar.
United had started the game well, but faded badly, perhaps lacking energy after the Chelsea game midweek. If Berbatov had converted either if two early, gilt-edged chances, the dream of a second Treble might well live on.
Instead, Arsenal have the chance to make it a very bad weekend for United by beating Liverpool today and adding pressure to the title run in. But this game ought to test Arsenal's own nerve aswell. Liverpool were impressive in dismantling City in their next game and Luis Suarez has added a much-needed new dimension to their attack. His strike partner Andy Carroll is exactly the kind of player who tends to trouble Arsenal's sometimes feeble backline. It remains to be seen whether the unexpected early returns of Szczesny and Djourou will lend the title charge a new impetus, or if the impotence of recent weeks will continue.