After 10 league games this season, United are on top with 24 points, thanks to draws at the Liberty Stadium and Upton Park where Chelsea and West Ham United denied title contenders Chelsea and Manchester City respectively.
Arsenal, on the other hand, failed to put up a fight against United at Old Trafford. It wasn't different before Jack Wilshere was sent-off as the Red Devils pushed forward relentlessly and had a chance to put the game to bed during the first half.
The Gunners went down earlier than expected, less than three minutes, when their former hero Robin van Persie lashed on to Thomas Vermaelen's miskick. The Dutch striker, however, muted his celebration out of respect to his former club.
Meanwhile, Chelsea were given a hard game agaisnt Swansea City ending up with a point after Spanish winger Pablo Hernandez scored with two minutes on the clock.
The Blues looked set to claim three points and eventually top position in the table when Victor Moses scored his first goal for his new club in the 61st minute. But the Welshside, who beat Liverpool in the League cup, were confident enough to snatch a point.
Roberto Mancini re-shuffled his starting XI for the clash against West Ham but that too, like the Champions League defeat to Ajax and the narrow win over Swansea, back fired the defending champions.
However, those two matches saw the Italian making several changes at the back, but against the Hammers Mancini opted to play Edin Dzeko, Mario Balotelli and Carlos Tevez for the first time. Had City gained three points, they would be on par with city rivals United at the top of the table.
Mancini surely has some work to do with his tactics, both upfront and at the back, as City failed to score in over seven months.
But it's too early to point out the league winners, even who will finish top four after just 10 games in this season.
United have so far lost two games but are on top of the table, Chelsea suffered their first defeat at the hands of United and currently second while City, still unbeaten, remain third.