[media-credit name=’Derek Montgomery’ align=’alignnone’ width=’648′][/media-credit]WEST LAFAYETTE, Ind. — The Wisconsin football team confirmed Saturday at Ross-Ade Stadium what has long been apparent: that its starting defensive line can dominate any opposing unit in the country — even the much-lauded offense of Kyle Orton's No. 5 Purdue Boilermakers.

Unfortunately for Badger fans, they made another point en route (one which, with Erasmus James set to miss at least the Northwestern game, could be pounded home in hurry): if a team lives by a unit, that team may well die by that unit.

For most of the first half Saturday, business went as expected — as usual — for the Wisconsin defense (which is to say, it was rendering the Purdue offense ineffective through overpowering line play).

James broke through Purdue's offensive line on a regular basis and — on the occasions that he wasn't held — made plays (two tackles, one sack, one forced fumble and one near-sack that resulted in a Scott Starks interception).

On the other end, Jonathan Welsh played his normal, quietly important role; he cut off Orton's escape routes, ran him around in the backfield and supplied constant pressure.

"We were very effective in the first half on defense primarily because we were able to get pressure with our two defensive ends," Alvarez said.

Anttaj Hawthorne and Jason Jefferson in the middle efficiently prevented the Purdue running game from affecting the game's outcome. The Boilers had averaged 157.8 yards per game on the ground in their first five games; they were on pace for 52 against the Badgers at the half.

And, like it has been all season, the result was jaw dropping: a shutout against a team averaging 41.8 points per game. Battles of attrition nearly always favor the better defensive squad.

"In the first half things went our way," defensive coordinator Bret Bielema said. "The things that we tried to do — what [the team] talked about — came through."

Then ironic fate struck the Badgers. Within two quarters of play, the Wisconsin defensive line went from being one of the most experienced and certainly the most dominant force in NCAA football to being an inexperienced liability.

In the second quarter, Welsh got his leg caught underneath him in the backfield; his ankle bent in a way it wasn't meant to and he spent the rest of the day in a walking boot.

In the third quarter, James became the second Badger to go down with an ankle injury. On a play called dead before the snap, Purdue tackle David Owen illegally chop blocked James, an infraction that resulted in no penalty but kept James limping the rest of the game.

"There are certain things that happen on the football field that I just don't think have a place in college football," Bielema said of the chop block.

Hawthorne left the game briefly minutes later with an injured calf and even Jefferson spent time on the sideline. With every single member of the vaunted unit limping around on the sidelines at various points by the fourth quarter, the Badgers — for the first time this season — showed signs of defensive vulnerability.

"[Injuries to the line] made a huge difference," head coach Barry Alvarez said after the game. "We played so well in the first half because we were able to get pressure with those ends. It's a different level of ball player. I don't know if anyone's been playing as well as [Erasmus James]. So we weren't getting the rush — you could see he had a lot more time to throw the football — and we weren't getting that kind of pressure on him. It was a different ball game for us in the second half."

The Wisconsin defense, perfect through two, found itself in a position where it was looking for anyone to step up.

"I don't know if I've ever been in a game like that," Alvarez said. "We were playing, probably, nine different guys."

The results were noticeable. Purdue immediately proved that all the scouts' claims that Anttaj Hawthorne is the best run-stopper in the nation are true. With Hawthorne slowed, the Boilers tripled their first-half run total in the second. The passing game saw a similar boost with pressure-creators James and Welsh sidelined — Orton threw for 139 yards, one touchdown and no interceptions in the second half.

"It just shows that you're only as strong as your weakest link," linebacker Dontez Sanders said.

With reserves like Jamal Cooper, Joe Monty, Justin Ostrowski, Kalvin Barrett, Mark Gorman and Brandon Kelly manning the line, the weakest UW link was decidedly weaker than normal.

"We had backups on the defensive line and backup linebackers and I thought they took advantage of that," Alvarez said.

The Badger defense was able to step up just enough to save a victory on the day in the end. Though they allowed Purdue to get into position for a final field-goal attempt and had to count on a miss by a kicker who never misses ("the wind was absolutely ridiculous," UW kicker Mike Allen said), UW took some positives from the experience.

"With the adversity that certain positions went through — as far as getting those guys banged up — those guys rolling up and doing what they needed to do was special," Bielema said.

"Nobody wants to be that one guy that let the other 10 guys down."