Class was in session for the Philadelphia schoolkids who "beat up" the Dallas Cowboys last week ... 'cause America's Team had the last laugh after beating the Eagles -- by punching back!!
The Cowboys stunned the defending Super Bowl champs with a 24-21 win at AT&T Stadium on Sunday ... and the players went crazy to celebrate taking down their NFC East rivals.
As part of the victory, the Cowboys didn't forget about the Philly elementary school that playfully trolled them ahead of the matchup with punching bags that had players' faces on them.
The Cowboys staffers were ready with tackling pads that had Eagles logos slapped on them .