Manchester United ended Arsenal's perfect start to the season as they came from behind to win 2-1 at Old Trafford in the Premier League.
Wayne Rooney earned and converted a penalty after 59 minutes before Abou Diaby headed through his own net four minutes later.
Andrei Arshavin had given the Gunners a 40th minute lead with a thunderbolt shot but Arsenal have only themselves to blame after gifting the defending champions both goals.
Arshavin, who had not scored in the Premier League since his four goals at Liverpool last season, broke the deadlock with a 25-yard screamer.
Only moments earlier the Russian was claiming a penalty after Darren Fletcher had made a sliding tackle on him but he took out his frustration in the best way possible with a rasping shot than Ben Foster got a hand to but could not prevent from nestling in the roof of the net.
Goal attempts had been limited up to that point with Arshavin coming the closest after Foster flapped at a corner. The former Zenit St Petersburg man opened his body but curled his shot just inches over the top corner.
United had their moments with Fletcher putting an early effort over the top from 12 yards and Rooney, playing on his own up front, curling a free-kick narrowly wide of the post.
Nemanja Vidic had a great chance to level on the stroke of half-time but he scuffed his shot from no more than eight yards.
Arsenal started the second period brightly and Arshavin's cross from the left was met by Robin van Persie but Foster made a superb save with his outstretched left foot to deny the Dutchman.
If Foster was partly culpable for the goal, he certainly made amends with that save and 10 minutes later his side were on level terms.
A long pass down the left channel from Giggs was collected by Rooney who went down under a challenge from the outrushing Almunia. It was a clear penalty and the United striker picked himself up to send the Spanish custodian the wrong way with his spot kick.
Van Persie struck the middle of the crossbar with a swinging free-kick from the right before Diaby gifted the hosts the lead.
Giggs swung in a free-kick from the right and inexplicably the French midfielder headed past Almunia under no real pressure.
Diaby almost made instant amends but after creating an opening with a superb mazy run, he dragged his shot wide of the far post from 14 yards.
The game then became scrappy with nine yellow cards dished out by referee Mike Dean.
Almunia denied Evra before both Nani and substitute Dimitar Berbatov spurned golden chances in added time to seal the victory.
There was still time for van Persie to have a goal disallowed after William Gallas strayed offside.
A frustrated Arsene Wenger was sent to the stands for comments made to the fourth official in the aftermath and he was surrounded by United fans as the final whistle went moments later.