Feb 4, 2002 8:28 AM

That's why they play the games.

The New England Patriots, 14-point underdogs, pulled off the biggest upset since Super Bowl III, defeating the St. Louis Rams 20-17.

The deciding points came as time expired when New England placekicker Adam Vinatieri booted a 48-yard field goal.

New England forced three St. Louis turnovers, including a Ty Law interception returned for a touchdown that gave the Patriots a 17-3 lead going to the final period.

St. Louis quarterback Kurt Warner rallied the Rams, rushing for one score and hitting Ricky Proehl for another touchdown that tied the game with under two minutes left.

Super Bowl XXXVI MVP Tom Brady passed the Patriots downfield with no timeouts remaining, setting up Vinatieri's game-winning kick.

The victory marked the greatest upset since Joe Namath and the New York Jets shocked the Baltimore Colts 16-7 in the 1969 Super Bowl.