Purdue held the Sycamores to 71 yards and four first downs in the first half.
Knauf took a handoff 16 yards for a touchdown on a sweep, and the Boilermakers took a 17-0 lead with 5:08 left in the third quarter.
Indiana State got on the board on a fourth-and-9. Perish found George Cheeseborough deep down the right sideline to cut Purdue’s lead to 17-7 with 2:44 left in the third quarter.
Griggs made another field goal early in the fourth quarter for Purdue, but Indiana State answered with a touchdown.
Indiana State got one more shot, taking over at the Purdue 41 with 46 seconds remaining. On the second play, Allen’s interception sealed the win for the Boilermakers.
NAVY 41, INDIANA 35
Keenan Reynolds rushed for 127 yards and three touchdowns, leading Navy to a 41-35 season-opening victory Saturday at Indiana.
The Midshipmen (1-0) played almost flawlessly, finishing with 444 yards rushing, no turnovers, five penalties and only three carries for negative yards.
Navy has now won 20 games over BCS foes since 2003 — the most of any non-BCS school in the nation during that span.
For Indiana (1-1), it was a huge deflation after a 73-35 victory over Indiana State.
But as the Hoosiers continued to score, the defense was confounded by Navy’s ground game and never even forced a punt.
Navy scored on its first three possessions, taking a 17-0 lead. Reynolds scored on runs of 1, 2 and 1 yard as the Midshipmen fended off Indiana’s rallies.
The up-tempo pace kept the Midshipmen, who made the trip from Annapolis, busy as they played and sang the school fight song, “Anchors Away” repeatedly. Family members of the military also made the trip, thanks in part to an undisclosed donation from Indianapolis Colts owner Jim Irsay.
But the Hoosiers were no match for Navy’s vaunted triple option.
Navy opened the game with 29 consecutive runs, churning out 212 yards in roughly 1½ quarters. The strategy allowed the Midshipmen to do two things: put points on the board and keep Indiana’s high-flying offense on the sideline.