Manchester, England:Arsenal midfielder Abou Diaby headed into his own goal to gift Manchester United a 2-1 victory and condemn his side to its first loss of the season in the English Premier League on Saturday.
Diaby was under no pressure from United when he turned in Ryan Giggs' 64th-minute free kick, giving the English champion its 1,000th home win in the top flight.
Wayne Rooney had leveled from the penalty spot five minutes earlier after Andrei Arshavin's thunderous strike gave Arsenal a halftime lead.
The Gunners thought they had made it 2-2 in the fifth minute of stoppage time when Robin van Persie's shot found the net, but it was ruled out because William Gallas was adjudged to be offside.
After two straight wins, Arsenal manager Arsene Wenger's frustration was clear as he kicked a water bottle high into the air and was sent into the stands by referee Mike Dean despite there being just seconds remaining.
"I didn't know you were not allowed to kick a water bottle, although it was a good kick," Wenger said. "What is most difficult to take is that we were the better team but still lost the game.
"We got punished on two goals. It is beyond belief. When you play like that to go home with no points is very difficult to accept."
But it gave Alex Ferguson the win demanded by the United manager after he highlighted improving against title-race rivals as crucial to the quest for a fourth straight Premier League crown.
"One down at halftime, it's always an uphill task against a team of Arsenal's capabilities," Ferguson said. "We had to dig deep and I think in fairness we really did perform well in the second half."
The first-half performance was uncomfortable viewing for Ferguson, with Arsenal clearly the better side.
Rooney had created an opening for United to go in front after 10 minutes, though, chipping to Darren Fletcher, but after chesting the ball down the Scotland midfielder volleyed over.
United goalkeeper Ben Foster, who was being watched by England assistant coach Franco Baldini, looked vulnerable after dropping Arshavin's early free kick.
He later hesitantly palmed away Robin van Persie's corner with one-hand and the ball dropped for Arshavin but the Russian's shot went over.
Arshavin, whose arrival in February helped to ensure Arsenal finished in the top four, felt he should have been awarded a penalty after Fletcher's sliding challenge.
"I believe it was a penalty," Wenger said.
A minute later Arsenal was in front when Arshavin was left in space 25 meters (yards) from goal to collect Alexandre Song's short pass, control it and, with Nemanja Vidic static in front of him, unleash a fierce strike inside Foster's near post.
But Foster came to United's rescue two minutes into the second half, blocking Van Persie's shot after the Dutchman met Arshavin's cross unmarked in front of goal.
Despite Ferguson resisting making any hasty changes, the match turned in United's favor in a tempestuous five-minute spell.
Rooney ran onto a pass from Ryan Giggs, was tripped by Manuel Almunia, and the England striker posted his 102nd United goal from the spot kick.
In an effort to follow instructions to restrain criticism of referees, Wenger merely remarked: "It was an Old Trafford dish."
What was not lost on Wenger, though, was the similarity to the manner in which Eduardo da Silva earned a penalty against Celtic on Wednesday only to be subsequently charged by UEFA.
"I can guarantee over the weekend I will be able to find 50 similar situations where UEFA must take action or they will have singled out Eduardo as a victim," Wenger said.
As tempers threatened to boil over at Old Trafford, both Rooney and defender Wes Brown were booked for kicking out at Diaby as he rampaged down the right flank.
The resulting free kick was swung in by Van Persie but hit the crossbar.
Having narrowly missed out on an equalizer, the Gunners were trailing when Diaby inexplicably headed Giggs' free kick past Almunia.
"There was not one United player around our players," Wenger said. "It was a lack of communication and in these situations I feel we lack experience. We couldn't finish the game off, but we had chances to kill the game. It's difficult to swallow tonight."
While Arsenal has six points after two matches, United has nine having played an extra match.