BY PAUL NEWBERRY

AP National Writer

ARLINGTON, Texas — The Steelers had all the momentum. The Terrible Towels were out in full force around Cowboys Stadium. Rashard Mendenhall took the handoff with every intention of moving Pittsburgh a little closer to completing an improbable comeback.

Then, a big hit, the ball popped out of Mendenhall's hands, and Desmond Bishop took off with it for the Green Bay Packers.

It would be the biggest mistake on a night filled with them for the Steelers. Green Bay hoisted the Vince Lombardi Trophy with a 31-25 victory Sunday.

Mendenhall's fumble on the first play of the fourth quarter — Pittsburgh's third turnover of the game — helped the Packers hold on after the Steelers attempted to rally from an early 21-3 deficit.