Manchester United ended Arsenal's perfect start to the season as Abou Diaby's own goal gifted the Premier League champions a 2-1 win at Old Trafford.
Diaby headed a Ryan Giggs free-kick into his own net on 64 minutes after Wayne Rooney's penalty had drawn United level following Andrey Arshavin's first-half opener.
Darren Fletcher volleyed United's only real chance of the first half off target on 10 minutes before Arshavin narrowly failed to find the top corner of Ben Foster's goal.
Arshavin could easily have earned the Gunners a penalty on 38 minutes following a rash challenge by Fletcher, but two minutes later the Russian maestro fired the visitors ahead.
Collecting the ball 30 yards from goal, Arshavin turned into space before firing a crisp drive which was helped on its way into the net by Foster.
Though Foster may feel he could have done better with the goal, he kept United in the game in the early moments of the second half when flicking out a foot to deny Robin van Persie from close range.
Foster's opposite number Manuel Almunia then allowed the hosts to draw level on 59 minutes as he brought down Rooney in the box and the United striker stepped up to send the Spaniard the wrong way from the spot.
Van Persie curled a free-kick from near the right touchline against Foster's crossbar on 63 minutes and just 60 seconds later United struck decisively.
Giggs whipped in a free-kick from the right and Diaby, under no pressure from a United player, headed the ball past the helpless Almunia.
Dimitar Berbatov and Nani both wasted golden chances to settle any late nerves before Arsene Wenger was sent to the stands after Arsenal saw a goal ruled out deep into stoppage-time after William Gallas had strayed offside.
A United win had all looked so unlikely at half-time, as Arshavin threatened to run riot.
The Russian might have scored earlier than he did too when Foster flapped at a Van Persie corner.
The former Zenit St Petersburg man made a conscious effort to place a shot towards the top corner. Foster was not the only anxious face to watch it drift narrowly wide.
Given what happened immediately afterwards, Foster would probably have preferred referee Mike Dean to have got his decision right when Fletcher slid into Arshavin and cut him down inside the box.
There could have been few clearer penalty claims and Dean was standing near enough to make the perfect decision. Inexplicably, he chose to say no.
Instead, Arsenal maintained their offensive. The impressive Denilson slid a pass through to Arshavin, who had found space between United's defence and midfield which Ferguson's team selection was supposed to prevent.
Quickly Arshavin turned and let fly with a rasper of a drive.
There was plenty of pace on the shot but England goalkeepers should really be doing better than pushing it into the roof of the net, as Foster did.
Nemanja Vidic came close to levelling straight away for the hosts but, as they trooped into the tunnel for a dismal half-time debrief, the best they could actually reflect on was Fletcher's early chance and a Rooney free-kick that curled narrowly wide.
Strangely given how one-sided the opening half had been, Sir Alex Ferguson did not try to change things during the interval. And his team were almost out of the game before he had retaken his seat.
Arshavin sped past John O'Shea as though the Irishman was not there to reach the by-line and picked out Van Persie with a teasing low cross that looked certain to be number two until Foster stuck out a leg to make a magnificent save.
At that point, there seemed to be only one winner. How wrong those doubters were as Ferguson's team surged back, Giggs the architect behind the comeback just as Arshavin had sparked Arsenal earlier.
The difference was Dean said yes when United claimed their penalty as Rooney went crashing to the ground after Giggs had supplied the pass that sent him through one-on-on with Almunia.
Questions were asked when Rooney did not take the one Michael Carrick missed at Burnley. There was no need this time as Rooney went straight for the ball, put it on the spot and promptly sent Almunia the wrong way.
Any pretence at defence was now swept away amid the fervour of an occasion that threatened to become a classic.
When Diaby was hacked at by Rooney and Wes Brown, both men were booked, Van Persie was offered the chance to curl a free-kick at Foster's goal which thudded against the crossbar.
A minute later, from a very similar position, United got their second.
In truth, Giggs' free-kick would not have threatened Almunia if Diaby had not stuck his head on it and deflected it straight into the corner of his own goal.
United substitute Berbatov hopelessly shot wide when through on goal before Nani missed a gaping goal after the Portuguese winger's first shot was parried by Almunia.
In the fifth minute of injury-time, Van Persie slid the ball past Foster, but the linesman's flag had already been raised after Gallas strayed into an offside position.
It was too much for Wenger, who lashed out in frustration and was sent to the stands by Dean. After a laughable delay as Wenger got as near to the action as he could by clambering onto the top of the dug-out, the Frenchman made his way to the tunnel, lingering long enough to witness the last dregs of an epic.