An instinctive improvised header from Ji-Sung Park was enough for Sir Alex FergusonÃ¢â‚¬â„¢s men, who have now gone 16 league games without losing – setting a new club record and firing them two points clear with a game in hand.
United’s defensive stability and hard-working midfield as they secured a vital win in the championship race.
Arsenal, who came into Monday night’s match top of the table, had only beaten United in two of their last 10 games at Old Trafford and had not won in Manchester since September 2006.
Both teams knew they could ill afford to lose – and it showed during a first half void of clear cut chances.
The best chance of the game fell to Nani in the 23rd minute after Arsenal centre-back Sebastien Squillaci failed to clear his lines and his poor header fell to the Portuguese winger, whose first-time volley on the stretch whistled past Premier League debutant Wojciech SzczesnyÃ¢â‚¬â„¢s right-hand post.
The home side took the lead four minutes before the break when Park scored his fourth goal against ArsÃƒÂ¨ne WengerÃ¢â‚¬â„¢s side. The South Korean showed great skill to arch his body to meet NaniÃ¢â‚¬â„¢s deflected shot and loop his header over the 20-year-old goalkeeper to give United the edge before half time.
United started the second half brightly and nearly doubled their lead when Wayne Rooney sent Anderson through, but SzczesnyÃ¢â‚¬â„¢s stood tall and saved the BrazilianÃ¢â‚¬â„¢s chipped effort.
Soon after Anderson robbed Jack Wilshere on the edge of the United box to start a counter-attack that finished with Nani blasting over from inside the box.
Edwin Van Der Sar then spilled a Samir Nasri effort but Nemanja Vidic did enough to stop Marouane Chamakh from converting the rebound.
With his side lacking their normal fluency and swift passing Wenger introduced captain Cesc FÃƒÂ bregas and Robin van Persie, but the double substitution failed to open up the game.
United had a chance to end the contest when they were award a controversial penalty in the 74th minute after Gael Clichy was adjudged to have handled the ball by linesman Dave Bryan.
Rooney stepped up to take the spot-kick but saw his effort fly over the bar and into the Stretford End.
The striker nearly made an amends five minutes later when he latched onto a long ball forward by Rio Ferdinand, but at full stretch Szczesny managed to parry away his lobed effort.
Questions will remain about ArsenalÃ¢â‚¬â„¢s temperament and ability to handle pressure after this match, while United ominously sit undefeated at the top of the table despite not yet hitting top gear this season.
Sir Alex praised his side’s defensive strength after the match. “Our back four were magnificent tonight,” he said. “With that foundation, it always gives us a chance.
“We have to play well to beat a team like Arsenal and I think we performed well tonight.”
He added: “WeÃ¢â‚¬â„¢ve got a difficult game against Chelsea on Sunday, itÃ¢â‚¬â„¢s a very important game to come. I think our form is improving, and with the back four playing like that it gives us consistency which always gives us a chance.”
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