The warning signs have been flashing for a while.
For one night, the Buckeyes resembled something like the 65th-best team in the country, a middle-of-the-road underdog passing 73 times with a stagnant running game while hoping to play catch-up against a high-scoring opponent on the road.
The Buckeyes lost 49-20 to the Boilermakers and fell from No. 2 to No. 11.
Ohio State's season came crashing down on Saturday.
OSU had two long drives in the first half that got to Purdue's 7-yard line and its 15-yard line and got only three points out of those drives.
Ohio State (7-1, 4-1 Big Ten) was one dimensional on offense with all but 76 yards of its 546 yards total offense coming on passes. They are beaten up physically and their psyche will be questioned after losing for the first time.
Purdue (4-3, 3-1) announced its intention to compete early in the game with a couple of defensive stops.
Head coach Jeff Brohm wasn't having it. Recent history at Ross-Ade hasn't been kind to the Buckeyes, either. It was Blough's third straight 300-yard game and his fourth this season. The Buckeyes got the yards, but not the points.
Twice, Purdue cornerback Antonio Blackmon broke up third-down passes in the end zone. That's largely a outcome of how one-dimensional they have become. The Boilermakers dominated the first half by playing keep away. Ohio State averaged only 3.0 yards on 25 carries. The Buckeyes still have a pair of huge games on the schedule against Michigan and Michigan State. On the next play, Blough hit Moore for a 9-yard touchdown and it was 14-3 at halftime.
Ohio State coach Urban Meyer said he was "very surprised" at how the game went. All of those numbers except the touchdowns were Ohio State records. After the Buckeyes scored to make it 28-13 with under 10 minutes left, some felt the comeback was on. Knox finished with 128 yards and three touchdowns.
Most of those games ended as everyone expected.
The first of those came with the help of two 15-yard Purdue penalties.
The Hoosiers added a late touchdown Peyton Ramsey's 21-yard pass to Harris, and recovered an onside kick.
After closing to 14-6 early in the third quarter, Davon Hamilton was called for roughing the kicker and the Boilermakers cashed in on their second chance with Knox's 1-yard TD run.
Ohio State's Paris Campbell Jr. heads up field as Purduecornerback Simeon Smiley closes in for the tackle at Ross-Ade Stadium on the campus of Purdue University Saturday.
Purdue quickly drove deep into Ohio State territory in the final minute of the second quarter.
Rondale Moore can't be stopped.