United looked set for a draw after Robin Van Persie had cancelled out Antonio Valencia’s opener but Welbeck’s finish keeps United within three points of City.
While the 8-2 demolition of Arsenal in the corresponding fixture in August was never going to be repeated, United were determined to turn their fortunes around on a ground where they had only won one out of their last five league meetings.
With Lindegaard confirmed in goal, Ferguson welcomed back Phil Jones in the middle of the defence, alongside Evans, with Smalling and Evra as fullbacks. Rooney and Welbeck were up-front,supported by Valencia, Giggs, Carrick and Nani in midfield.
After a slow start United started dominating possession but were soon dealt a blow as Phil Jones left the field on a stretcher after twisting his ankle and had to be replaced by Rafael.
Giggs and Carrick were superb in midfield with Nani tormenting Djourou down the left channel time and again.
The Portuguese showed the best and worst of his repertoire, getting past Arsenal’s right back – for a team like Arsenal, with a fine tradition in that position, Djorou is an embarrassment – before shooting wide instead of setting up Welbeck for a simple finish.
Was then Evra’s turn to take Djorou to the cleaners, as he played a clever ball to Nani ,whose sidefooted effort was parried by Szczesny.
The United captain produced his best performance of the last two seasons, solid at the back and bombing forward with ease to exploit Arsenal’s defence.
It was no surprise that the assist had come from the left, as United were rampant down that flank.
Arsenal started the second half in inspired fashion and United were let off the hook with 51 minutes played, as Van Persie squandered a great chance from close range, after having being set up by Rosicky.
Ramsey and Oxlade Chamberlain then fired over and wide respectively, as United struggled to keep possession of the ball.
Welbeck could have finished Arsenal off with 25 minutes to go, but saw his effort cleared off the line by Mertesacker having beaten Szczesny.
With 20 minutes left on the clock Arsenal drew level through Van Persie.
Rafael was caught out of position after having broken forward and the excellent Oxlade-Chamberlain set up Van Persie,whose finish across the goal went through Evans’legs and into the bottom corner.
Oxlade-Chamberlain was the substituted by Arshavin, a move that Arsenal fans were quick to remind Wenger at the final whistle.
Scholes and Park replaced Nani and Rafael as United looked to hang on to the game.
Over the last few years Arsenal had snatched victory in the closing stages against United, but this time it wasn’t to be, as Valencia shrugged off Arshavin to tee up Welbeck for his sixth league goal of the season.
The England striker made no mistakes from close range, sending the away end berserk as he joined the fans to celebrate what could be a crucial win, while Arsenal were left to face a third consecutive league defeat.