New England attacked from the start, but several big saves from FCD goalkeeper Raúl Fernández kept the scores level until late on when it seemed as though Kenny Cooper had put the visiting side in front. The big forward collided with New England's Bobby Shuttleworth, leaving the goalkeeper stranded as Cooper flicked a header into the net, only to be ruled offside.
But in the 87th minute Perez snatched the win for the Texas club. The Panamanian forward got his head on a ball in from David Ferreira and buried it back across Shuttleworth to snatch all three points.
The win is Dallas' third in a row.