Andy Mitten watched the striker make the difference against his former club and carry on his goal-a-game start to life in Manchester.
Robin van Persie has wasted no time at Old Trafford
When the Dutchman's name was read out before kick-off, it was roundly booed by the visiting supporters, who then sang several songs about the striker which are not decent for reproduction in a family newspaper.
The 73,000 Manchester United fans at the ground have been delighted with his goal-a-game performances in league starts so far.
It is not just Van Persie's nine goals and the sublime manner in which some of them have been scored which have endeared the club's biggest summer signing to United fans. Van Persie has won more free kicks than any other United player, and had more shots on target, too. There are no guarantees when signing even big name players, but the man from Rotterdam is proving to be every bit the star the fans hoped he would be.
His former teammates were enthusiastic in their pre-match handshakes, although they knew that danger awaited from the striker they used to work with every day. They were also desperate to avoid anything near to a repeat of last season's scoreline, when United won 8-2 at Old Trafford.
Arsenal got off to an atrocious start. Just two minutes were gone when Rafael da Silva sent a low cross from United's right.
Thomas Vermaelen failed to clear beyond the path of Van Persie on the edge of the area and the Dutchman finished first time with an exquisite strike which beat the goalkeeper Vito Mannone before jogging towards the nearby Arsenal fans.
He did not overdo the celebrations, merely raising his hands to shoulder height, but seeing an ex so happy with a new partner is not easy to stomach and it brought another flurry of abuse from the Gunners fans.
Van Persie is not a player who sets the tempo of a game, nor sees as much of the ball as those behind him. He spent the rest of the first half waiting. Waiting near the halfway line in a deep position, waiting ahead of his strike partner Wayne Rooney in a more advanced role.
While Rooney sprinted and harried, Van Persie jogged unhurriedly and intelligently into positions, his 1.86m frame less mobile but more elegant than Rooney's.
They combine well and supported on each wing by Ashley Young and Antonio Valencia, the pair were always the game's most potent threat - not difficult against a curiously limp Arsenal.
In one such instance, Rooney released Van Persie to shoot towards goal on 21 minutes. Rooney is the established striker at Old Trafford, but his status as United's penalty taker will surely be challenged by Van Persie after Rooney missed a 45th-minute spot kick.
Sir Alex Ferguson was concerned with the Rooney's poor penalty-taking record at the start of the year, but while Van Persie took Arsenal's penalties last season, he is not Rooney's obvious successor as he, too, has missed from the spot this season.
Rooney has missed seven of his 20 Premier League penalties and United have scored just one of their past five. In a bizarre half-time exchange, Andre Santos and Van Persie swapped shirts in the Old Trafford tunnel, a move unlikely to go down well with Arsenal fans.
United continued to spurn chances after the break and Van Persie continued to be central to the home threat as he supplied a clever cross for Valencia to miss. He also crossed to Anderson who saw his effort correctly disallowed for being offside.
A soon-to-be-red-carded Jack Wilshere offered Van Persie his hand after fouling him, but the Arsenal players were less respectful when Van Persie was yellow carded in the 59th-minute for a challenge on Bacary Sagna.
"Van Persie, you know what you are," the Arsenal fans chanted, cryptically. "Oh, Robin van Persie," replied the Stretford End, before the Dutchman beautifully controlled a Young cross with his left foot, then saw his instinctive shot with the same foot saved.
Such moments of artistry are the preserve of the finest footballers. And Van Persie is one of those.
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