Ronaldo & United Lose
Cristiano Ronaldo and his Manchester United team-mates were left rueing missed chances as Arsenal got their Premiership campaign back on track.
United boss Sir Alex Ferguson will have been frustrated by his side's wastefulness, with Wayne Rooney and Cristiano Ronaldo guilty of throwing away obvious openings.
It was United who had the first opportunity when Arsenal keeper Almunia inexplicably picked up a backpass from Mikael Silvestre inside the first two minutes. Arsenal were relieved when Anderson's free-kick was half-cleared and Michael Carrick turned the loose ball wide.
Wenger appeared to have instructed Arsenal to probe United's right-flank, where Gary Neville looked desperately uncomfortable at the start of what was a harrowing afternoon for the England defender. Gael Clichy's cross was headed off target by Nicklas Bendtner, who then failed to get on the end of another dangerous ball from Nasri.
Rooney missed an even better chance for United after 17 minutes, carelessly lofting an inviting ball from Ronaldo over the top when it seemed certain he would score.
Arsenal took full advantage of the reprieve to take the lead five minutes later, when Nasri's shot took a crucial deflection off Neville and wrong-footed Edwin van der Sar. It was a wonderfully open game but Arsenal were playing like a team stung by recent criticism and the sight of old rivals United had only inspired them further.
Fabregas had a shot deflected just wide but United were threatening themselves and Almunia needed to save well from Ji-Sung Park.
If there was a frustration for Arsenal, it would have been that the crucial second goal had eluded them, despite their dominance. They did not have to wait long to get it as Nasri doubled their advantage three minutes after the restart. Fabregas was at the centre of affairs again, punishing United for failing to pick up Nasri when he threaded through a perfect pass for the France midfield man to beat Van der Sar with an emphatic finish.
United, uncharacteristically, were lacking a cutting edge and wasted a perfect opportunity to grasp at a lifeline immediately after Arsenal's goal. Park found Ronaldo unmarked at the far post but he dragged his shot across the face of goal with only Almunia to beat.
Almunia then required lengthy treatment after an accidental clash with Carrick as United refused to give up on the belief that they could get back into an enthralling encounter. He carried on but was clearly in discomfort and was replaced by Lukasz Fabianski with 12 minutes left.
United also replaced Rooney with Carlos Tevez and Anderson with Ryan Giggs in what was clearly a last throw of the dice by Ferguson as time ran out. Rafael, who had replaced Neville in the 63rd minute, pulled one back in the final minute with a spectacular left-foot volley from the edge of the box after Arsenal failed to clear a Giggs cross.
Arsenal: Almunia (Fabianski 78), Sagna, Gallas, Silvestre, Clichy, Walcott (Song Billong 77), Fabregas, Denilson, Nasri, Diaby (Toure 86), Bendtner.
Subs Not Used: Vela, Ramsey, Wilshere, Djourou. Booked: Gallas, Sagna, Clichy.
Goals: Nasri 22, 48.
Man Utd: Van der Sar, Neville (Rafael Da Silva 63), Ferdinand, Vidic, Evra, Ronaldo, Anderson (Giggs 72), Carrick, Park, Rooney (Tevez 77), Berbatov.
Subs Not Used: Kuszczak, Nani, O'Shea, Evans.
Booked: Evra, Carrick.
Goals: Rafael Da Silva 90.
Att: 60,106
Referee: Howard Webb (S Yorkshire).