The One With The Rumor - S8-E9
Corrected entry: Even though Chandler and Phoebe say they don't really watch the football game, it seems as though they agree that Detroit Lions won the game. But the 2001 Thanksgiving Day game between the Lions and the Packers were indeed won by the Packers.
Correction: You missed the whole point - they say they don't watch the game and then they guessed the wrong winning team.
MovieFan612