The Cowboys improved to 11-4 on the season and have clinched the NFC East title.
As Washington fell apart at the AT&T Stadium, tempers also flared on the sideline. Defensive linemen Jonathan Allen and Daron Payne, who were teammates at Alabama, got into an altercation that NBC's broadcast caught on camera.
Payne appeared to stick a finger in his teammate's face and Allen retaliated by throwing a punch.
"I don't think it takes a rocket scientist ... If you look at how that game went, emotions are high, things are high, things happen," Allen told reporters after the game when he was asked about the altercation.