It was a night to forget for Manchester United as Arsenal advanced to the FA Cup semi-final and out-of-sorts winger Angel di Maria was sent off for pulling at referee Michael Oliver's shirt. Despite Wayne Rooney levelling with his head after Nacho Monreal's opener, the night belonged to former United striker Danny Welbeck, who sealed the Gunners' victory with a beautifully composed finish. Here, Sportsmail's Neil Ashton rates every player's performance at Old Trafford. Arsenal's Danny Welbeck emphatically celebrates his goal, which went on to be the winner against his old club . MANCHESTER UNITED (4-1-4-1) David De Gea: No chance with Monreal finish. Exposed brutally by Valencia when Welbeck raced through to score. Pulled off a couple of world class saves towards the end. 7.5 . Manchester United goalkeeper David De Gea had a solid game but was exposed for Arsenal's second goal . Antonio Valencia: Powered forward with lung-busting run for United equaliser. Dreadful, dreadful back pass for Arsenal’s second. 6.5 . Chris Smalling: Solid without every really imposing himself. Has taken it upon himself to marshall back four. 6.5 . Marcos Rojo: Rock solid. Is he turning into United’s best defender? Granted, not a great deal of competition, but he is playing well. 7 . Despite the loss Marcos Rojo was one of United's top performers with some solid defending . Luke Shaw: At the mercy of van Gaal’s half-time tactical switch. Was neither good nor bad. Seemed a bit unfortunate to be hooked. 6.5 . Daley Blind: Hard to work out exactly what Van Gaal is asking him to do in there. Just seems to spend the entire game chasing after the ball. 6 . Angel di Maria: Has clearly gone mentally - should not be playing. Booked for foul, stupid to tug referee’s shirt. Went to sleep when Monreal made his run down the left in build up to Arsenal goal. Sweet cross for Rooney equaliser. 4 . United winger Angel di Maria tugs at Michael Oliver's shirt before seeing red at Old Trafford on Monday night . Di Maria trudges off the pitch after being sent off for his stupid reaction . Ander Herrera: Finally booked in 38th minute - amazing Michael Oliver took so long. Speed of game took him by surprise. Replaced by Carrick. 6 . Marouane Fellaini: One of the most prominent players in the team. Lovely 20 yard chip forward for Rooney’s one touch takedown before half time. Had chance to score too. 7.5 . Marouane Fellaini (right) tussles for the ball with Arsenal's dogged midfielder Francis Coquelin (left) Ashley Young: Hugged the touchline, but United should have got him on the ball more. Has legs to stretch defences. 6.5 . Wayne Rooney: Love affair with scoring in the FA Cup continues. Now has to find a way to win it. Breathtaking take down just before half time from Fellaini chip. 7 . Manchester United striker Wayne Rooney heads home the equaliser against Arsenal at Old Trafford . SUBSTITUTES: . Phil Jones (Shaw 46): Didn’t know whether to stay or go when Ozil or Welbeck dropped off. 6 . Michael Carrick (Herrera 46): Usual nice touches in midfield. 6.5 . Adnan Januzaj (Rojo 73): Brought on to give United life. By then they were dead. 6 . SUBSTITUTES NOT USED: Rafael, Mata, Falcao, Januzaj, Valdes. BOOKED: Herrera, Fellaini, Young. SENT OFF: Angel di Maria . MANAGER: Louis van Gaal: Tactical genius? Bladdered two players unnecessarily at half-time. Looks like yesterday’s man. Heading same way as Moyes at this rate. 3 . Di Maria makes the long walk towards the Old Trafford tunnel after being sent off . ARSENAL (4-2-3-1): . Wojciech Szczesny: Very little to do apart from Rooney’s goal, which he had no chance of doing anything to stop. 7 . Hector Bellerin: Early booking, cleaned out Young. Disciplinary tight-rope after that trying to stop the United winger 7 . Per Mertesacker: Left Koscielny exposed when Rooney scored, just seemed to switch off. Improved as game progressed. 7 . Per Mertesacker (right) and Laurent Koscielny allowed Rooney the space to head home United's equaliser . Laurent Koscielny: Lost Rooney for the United equaliser, allowed him to squeeze in to space behind him. 7.5 . Nacho Monreal: Showed ambition down the left when he kept on running after exchanging passes with Ozil in build up to goal. 7 . Nacho Monreal slips the ball past the oncoming Manchester United goalkeeper David De Gea (right) Francis Coquelin: Screening job in front of Arsenal’s back four, rarely left his post. Turning into Mr Reliable. 7.5 . Francis Coquelin showed he is an indispensable player for Arsene Wenger after a solid midfield performance . Santi Cazorla: Switched roles when Ramsey came on, playing in a more advanced position. 7 . Alex Oxlade-Chamberlin: Lovely, jinking run for the opening goal. Arsenal’s best player until he pinged left hamstring. 7.5 . Alex Oxlade-Chamberlain is floored after seemingly pulling his hamstring in the second half . Mesut Ozil: Clever pass into the feet of Oxlade-Chamberlain in move for Arsenal goal. Lovely lob wedge into Welbeck for penalty appeal. 7.5 . Alexis Sanchez: Such a willing worker, tireless up and down the flank. Flashes of his ability, but lacked his usual goal threat. 7 . Danny Welbeck: Kept his composure to put Arsenal back in front when her took the ball round De Gea with class and conviction. Good on him for that. 8 . Welbeck rounded De Gea with the deftest of touches before slotting home coolly against his former side . SUBSTITUTES: . Aaron Ramsey (Oxlade-Chamberlain 50): Unexpectedly thrust in at start of second half. 7 . Calum Chambers (Bellerin 65): Composed, looked the part when he came on. Added attacking threat too. 7 . Olivier Giroud (Welbeck 73): Came on for Welbeck to add physical presence to see this game out. 7 . SUBSTITUTES NOT USED: Gibbs, Walcott,  Martinez, Akpom. BOOKED: Bellerin. MANAGER - Arsene Wenger: Inspired decision to play Danny Welbeck against his former club. Arsenal’s name is on the Cup. 8 . REFEREE - Michael Oliver: Strong, one of best performances of season in this field. Character to send off Di Maria and it was the correct call. 8.5 . Arsene Wenger (centre) raised a few eyebrows for starting Welbeck, but his decision certainly paid off .
Arsenal striker Danny Welbeck scored the winner against his former club . Angel di Maria was dismissed for dissent after pulling the referee's shirt . Nacho Monreal opened the scoring and Wayne Rooney equalised but Welbeck's finish earned him the plaudits .