Daniel Taylor at Old Trafford for the Guardian.co.uk
Robin van Persie celebrated in the manner of someone who wanted to respond to ArsÃ¨ne Wengerâ€™s assertion that he was still, deep down, an â€œArsenal man.â€ Yet again, he had reminded his old club of his uncommon gifts in the penalty area and this time there was none of the restraint that has accompanied the previous occasions. Van Persie was off, running to the touchline to embrace Wayne Rooney and screaming at the crowd.
David Moyesâ€™s team had to endure some concerted pressure after that first-half header and there was some unashamed conservatism from Unitedâ€™s manager in the final exchanges when the electronic board went up to signal that Van Persie was being replaced and Marouane Fellaini was taking his place. Yet United gave everything to hold on to their lead. At one point Rooney could be seen making a decisive tackle on the edge of his own penalty area. The next challenge was his as well, after sprinting 70 yards to the right wing. Rooney, once more, had typified Unitedâ€™s spirit of togetherness.
The champions had played the second half without Nemanja Vidic because of the whack he took to his head in a collision with his goalkeeper David de Gea. Rio Ferdinand was already missing and, with Chris Smalling deputising for Rafael da Silva, that meant them playing 45 minutes with three quarters of their first-choice defence missing. Yet Arsenal had played with a strange lack of creativity throughout. Wengerâ€™s men had plenty of the ball, particularly in the second half, but their substitute, Nicklas Bendtner, could not reach Bacary Sagnaâ€™s right-wing delivery in stoppage time and that was probably their most inviting chance. That Bendtner was on the pitch anyway probably just brings it home to Arsenalâ€™s supporters that there are still deficiencies in Wengerâ€™s team.
Arsenal will possibly reflect Van Persieâ€™s goal might have been avoided if Per Mertesacker had not been missing because of a virus that has swept through their camp over the last few days. Tomas Rosicky was also missing but there were other players who battled on and perhaps it contributed to a lessening of their usual sureness of touch.
To use it as an excuse, however, would be to ignore the fact they had actually improved in the first half. Before then, there was the unusual sight of Mikel Arteta just blindly kicking the ball straight to an opponent and, even stranger, Mesut Ã–zil trying a pass out to the left and knocking it straight out of play. Giroudâ€™s ability to bring other players into the game was only sporadically evident and, for all the refinement in the Arsenal midfield, the outstanding performer during that period was Phil Jones, clattering into tackles, driving forward and fully justifying his selection ahead of Fellaini.
Vidicâ€™s injury meant Jones going back into central defence alongside Jonny Evans for the second half and there were times undoubtedly when United were guilty of defending too deeply. Arsenal flooded forward but with little penetration and Chris Smalling could have soothed Old Traffordâ€™s nerves with a clear header from Patrice Evraâ€™s free-kick.
Yet the league leaders simply did not have enough wit to break down their opponents after that moment, with 27 minutes gone, when Rooney sent over a corner and Arsenalâ€™s preference for zonal marking meant Van Persie could attack the ball without anyone following him. That extra leverage was crucial in helping him get above Giroud but it would not be fair to apportion the blame towards the Frenchman. The fact is Giroud was just trying to compensate because Aaron Ramsey had strayed from his position.
Van Persieâ€™s was the most decisive act and his header flashed past Wojciech Szczesny and over Kieran Gibbs at the far post.