Crosby's third field goal of the game climaxed a wild comeback for the Packers, who with 35 seconds to play got both an 11-yard touchdown pass from Graham Harrell to Ryan Taylor and a two-point conversion throw from Harrell to Taylor.
That brought about a 21-21 tie and the Packers then recovered the onside kick. Harrell moved Green Bay 20 yards in four plays to set up the game-winning kick.
Green Bay starter Aaron Rodgers completed 19-of-23 passes for 204 yards and a touchdown in the opening half. His scoring throw was for 18 yards to Jermichael Finley.
Curtis Painter, starting in place of the injured Indianapolis quarterback Peyton Manning, threw for 171 yards and two touchdowns.
Green Bay is 2-1 in the exhibition season. Indianapolis has yet to win in three outings.