IOWA CITY - In a dream Iowa Hawkeyes season filled with perfect twists and turns, one bad twist turned Iowa's perfect season into an empty dream.

With his team on top 10-0 early in the second quarter of a Kinnick Stadium meeting with Northwestern, Hawkeyes quarterback Ricky Stanzi got turned the wrong way in the Iowa end zone.

A subsequent sack and strip by Wildcats defensive end Corey Wootton led to a Northwestern touchdown. The sprained ankle Stanzi suffered on the play all but led to the first loss of what had been a star-kissed Iowa season.

"It's a good play on their part, a bad play on ours," Iowa coach Kirk Ferentz said after his team lost 17-10. "Cost us a touchdown and a quarterback, unfortunately."

Behind relief quarterback James Vandenberg, a redshirt freshman, the Hawkeyes

couldn't muster any more points. They saw their hopes for an unbeaten season, if not a national championship opportunity, fall by the wayside three games short of the finish line.

"That was always in the back of my mind," junior receiver Derrell Johnson-Koulianos said. "It has never been done here before, and it is something I really wanted personally and for everybody. Now that opportunity, in the blink of an eye, it's gone. The best we can do now is 11-1."

The quest for that will starts next week in Columbus, Ohio, where the 9-1 Hawkeyes can stay alive in the hunt for a Big Ten Conference championship.

Ferentz said they almost certainly will have to do that with Vandenberg, not Stanzi, under center. The coach said a preliminary X-ray of Stanzi's sore right ankle did not reveal a break.

"The bad news is it's a severe sprain," Ferentz said. "My guess is he will be out of action here the next couple of weeks."

That means Vandenberg will get a couple of opportunities to improve on a

9-for-27, 1-interception, 82-yard passing performance in Saturday's relief effort.

A Keokuk, Iowan 17 days shy of his 20th birthday, Vanderberg's previous collegiate experience amounted to six plays at the end an early-season blowout over Iowa State. Three plays into Saturday's test, Vandenberg had his first throw intercepted by Wildcats linebacker Quentin Davie at the Hawkeyes' 46. Ten plays later, Northwestern had covered those 46 yards, scoring the go-ahead touchdown on a 4-yard, Dan Persa pass to Blake Dunsmore.

Northwestern later added a 47-yard, fourth-quarter field goal for the only points of the second half.

Iowa's defense performed well, limiting the visitors to 239 yards, but Iowa's offense turned the football over four times in the second quarter and managed 121 total yards with Stanzi sidelined. The Hawkeyes ran for only 65 yards.

It was a frustrating development for a team that started the game with much promise. Stanzi hit Marvin McNutt for a 74-yard score on Iowa's third snap and the Hawks added a 39-yard Daniel Murray field goal on their next possession.

Stanzi was 4-for-8 for 134 yards passing with a second-quarter interception before he went down.

The Hawks did have a chance for more late-game magic, taking their last turn with the football with 2:04 remaining in the game and 83 yards to cover. The drive ended on four straight incomplete passes.

No perfect ending this time in a loss that stunted an Iowa winning streak at 13 games.