Wayne Routledge scored the opener and made the winner for Wilfried Bony as Swansea upset Manchester United in the FA Cup to earn their first ever win at Old Trafford. Javier Hernandez gave the hosts parity, but they later saw Fabio sent off. Swans winger Routledge stunned the Theatre of Dreams by chipping Anders Lindegaard and giving the visitors an early lead. He was set away between the United centre backs by Alejandro Pozuelo's reverse pass on 12 minutes for his fourth of the season. The visitors only enjoyed a brief lead, however. David Moyes's men equalized after a quarter of an hour when Hernandez ended his goal drought by converting a whipped in Alex Buttner cross from close range. Antonio Valencia then blazed over from another decent Red Devils move following good work by Danny Welbeck. Goalmouth action abated thereafter until Chico Flores's clumsy challenge on Hernandez brought the hosts a free kick. Buttner's low effort went straight at Gerhard Tremmel 12 minutes before half time. Either side of the break both sides continued to largely cancel on another out. Moyes and Laudrup looked to their benches to change that. Swansea sent on Jose Canas for the ineffectual Jonjo Shelvey, thus freeing up Jonathan De Guzman to play further forward, after United introduced talented youngster Adnan Januzaj. The visitors in their alarming yellow and purple away kit enjoyed plenty of second half possession without penetration. Rio Ferdinand hobbled off 15 minutes from time, so the Red Devils were forced into a defensive change. Chris Smalling moved to centre half and Fabio came on. He was only on the field briefly, however. Referee Mike Dean brandished a straight red card for the Brazilian fullback after he caught Canas high with his studs. Laudrup threw on an extra striker in Alvaro Vazquez for the closing stages, but this tie looked like fizzling out. Bony struck in the final minute before stoppage time, however, to snatch victory for the Swans. The Ivorian, who hadn't had a sniff all match, nodded in Routledge's near post centre and home fans streamed for the Old Trafford exit. United have two legs of the Capital One Cup semi-final coming up and that will soften the blow. Moyes is under huge pressure to win that competition now. Swansea visit this stadium again on Saturday in the Premier League and revenge may be meted out.