Jamie Foxx was FEEEEEEEEEELLLLIIINNNN' himself after the Cowboys beat the Saints ... 'cause dude broke out ALL his Dallas jerseys and had a dance party in his living room!!
The 'Boys scored a massive win over New Orleans on Thursday night in a game nobody predicted them to win ... and Foxx turned up like they just earned the Lombardi Trophy.
Jamie -- rockin' an Emmitt Smith throwback -- threw down some epic dance moves to "We Dem Boyz" ... and then started the trash talk.
"I told y'all! Don't ever go against us! We them boys! I told y'all, them Saints was going to be turning into Aints today! I told ya!"
Jamie then took aim at ESPN personality and noted Cowboys hater Stephen A. Smith, saying, "First of all, you have to understand that the Cowboys are America's Team, and now you understand why!"
Jamie's got every right to be happy ... the win was pretty dope -- but nobody tell him Dallas is just one game away from being out of the current playoff picture.
Seriously -- nobody kill his chill!!!!