MADISON, Wis. -

What seemed like a prototypical early-season rout turned into a dogfight late in the fourth quarter as No. 12 Wisconsin barely held off Northern Iowa 26-21 in the season opener.

The win was Wisconsin's 33rd straight regular-season nonconference victory and 17th consecutive home victory.

Badgers head coach Bret Bielema was pleased with his team's attitude and mentality against what he said was "probably the best FCS team we've ever faced."

"I told our guys any win is a good win, but this was one of the most beneficial teaching tools we could secure," Bielema added.

Down 19-0 with 6:54 left in the third quarter, the Panthers would score on three consecutive drives to pull within five, 26-21, at the 8-minute mark of the fourth quarter.

Northern Iowa forced a 3-and-out from the reigning Big 10 champs to get the ball back at its own 25-yard line.

Redshirt freshman Sawyer Kollmorgen made a rousing debut in the comeback attempt, twice completing on 3rd-and-10. The comeback was not to be as the drive ended with a ball batted down at the line of scrimmage on 4th-and-1 from the Badger's 41. Kollmorgen finished his debut with 265 yards and three touchdowns while redshirt sophomore running back David Johnson caught four passes for 107 yards and two touchdowns.

"When you play a team like Wisconsin, you can draw all the X's and O's that you want, but until you can line up and beat them at the line of scrimmage, you have no chance," Panthers head coach Mark Farley said. "The factor of [our line] starting to stay with the play longer from offensive line to receivers, I think everything started to come together."

Junior transfer Danny O'Brien stepped on to Camp Randall Stadium for the first time, replacing third-round NFL draft-pick Russell Wilson. O'Brien completed 19 of 23 passes for 219 yards and two touchdowns, numbers Bielema called very impressive for a first-time quarterback.

"I like the fact that he didn't turn the ball over," Bielema noted. "There are going to be some things that he's going to see on film that he can pick up, but he made some great decisions."

Senior Monte Ball began his campaign to win this year's Heisman Trophy with a heavy workload, rushing for 120 yards and one touchdown on 31 carries. Ball also caught three passes for 31 yards. Jared Abbrederris led all Wisconsin receivers with six receptions for 84 yards and two touchdowns.

"This was a great learning experience for us all," Ball added. "It's a lot easier to correct your mistakes after a win, of course."

Northern Iowa was limited to less than 7 minutes of possession in the first half with only one drive resulting in the chains moving more than once. The Panthers finally broke through late in the third quarter with a 13-play, 75-yard drive to make it 19- 7. Facing 4th-and-4 Kollmorgen hit Brett LeMaster for a 24-yard completion inside Wisconsin territory, the longest pass up to that point, and followed up with a 2-yard touchdown completion to Chad Owens three plays later.

O'Brien and company responded with a touchdown of their own, as the transfer hit Abredderis for a 53-yard touchdown three minutes later.

The Panthers, now awakened, hit back with a score of their own a minute later as David Johnson broke two tackles after catching a Kollmorgen pass, taking it 55 yards to paydirt. Emboldened after a defensive stop, the Panthers' offense sliced through the Badgers.

The Badgers had opened the game with a 14-play, 61-yard drive that culminated in a 32-yard field goal and set the table for what was to come throughout. Ball rushed for 25 yards on eight carries, chipping away at the Northern Iowa defense without being able to break through a stacked line.

Facing 3rd-and-22 from his own 47-yard line, O'Brien stepped out of Wilson's long shadow for his longest completion of the half, a 22-yard pass that led to a touchdown five plays later and gave Wisconsin some much needed breathing room, a 13-0 lead going into the intermission.

NOTES: Wisconsin has won 15 consecutive season openers, the third-longest active streak in the nation behind only Nebraska (26) and Florida (22). … David Johnson almost matched his receiving touchdowns from last year (3), catching two in the game. … Wisconsin went six games before recording a single-digit victory last season.