The Denver Broncos are in the Super Bowl against the Seattle Seahawks and one reason was due to the play that Wes Welker made that allowed Demaryius Thomas to get open, as the WR collided into Aqib Talib on a passing route that knocked him out of the game.
Welker did not get flagged on the play and afterwards his former coach Bill Belichick called it one of the worst plays he had ever seen and thought it was dirty. It wasn't the only play that ended up factoring into the outcome of the game, but it really hampered the Patriots in the passing game on defense when Talib went down. Take a look for yourself.
Welker angle one:
Welker angle two: