CHATTANOOGA, Tenn. -- With its quarterback limping around, Appalachian State's defense delivered the school's first I-AA national championship.
Jason Hunter returned a fumble for a go-ahead touchdown in the fourth quarter as the Mountaineers beat Northern Iowa 21-16 for the crown on Friday night.
"It was a great night. It speaks wonders for our program, our school," Appalachian State coach Jerry Moore said. "I can't say enough about our defense. They were tenacious."
The Mountaineers (12-3) trailed most of the game and quarterback Richie Williams, the Southern Conference offensive player of the year, didn't start but came off the bench to give it a go on a bum leg.
Both teams were in the title game for the first time, and Northern Iowa (11-4) appeared to be en route to the trophy until the fourth quarter.
The Panthers were ahead 16-14 when Appalachian State's Marques Murrell sacked Eric Sanders and forced a fumble at the 15. Hunter picked it up and ran in for a touchdown -- his third defensive score of the season -- to give the Mountaineers the lead with 9:14
Neither team could score afterward, and the Mountaineers sealed it with a first down with 1:36 remaining. Their fans clad in black and gold mobbed the field as time ran out.
"I saw the ball on the ground. I tried to pick it up as fast as I could," said Hunter, who led the team with 10 tackles and had two sacks.
Appalachian State kept the game close despite having three turnovers in the first half, but the Mountaineers' defense held Northern Iowa to two field goals and a touchdown.
"It's disappointing, of course, but at the same time we've had a great season with a great group of players," Panthers coach Mark Farley said. "It's a game of inches, and in this one we didn't have the inches fall in our direction."
Trey Elder started in place of Williams as expected and played all of the first half except the final play when Williams came in to throw a long pass that was broken up in front of the goal line.
Williams, a senior, strained a tendon in his left ankle early in last week's semifinal win over Furman. He ran for 1,009 yards in an option offense this season but was severely limited Friday night and finished 10-of-26 for 129 yards.
"It was frustrating. Coach told me though that we were going to wing it," Williams said. "Coach called option one time and I called timeout because I knew I could not run the play."
Appalachian State's Zach Johnson had six catches for 101 yards.
The Mountaineers were held to a season-low 46 yards rushing. Northern Iowa's David Horne had 102 yards rushing on 22 carries.
Sanders, a sophomore who joined the Panthers as a walk-on, went 17-of-31 for 181 yards.
Northern Iowa was ahead 16-7 at halftime, but Appalachian State cut it to two points in the third quarter when Williams directed a TD drive that was capped by Kevin Richardson's 1-yard run.
The Panthers scored 13 points in the second quarter following turnovers.
Northern Iowa's Tanner Varner intercepted a pass by Elder at the Appalachian State 41, and Horne scored a touchdown from 2 yards out five plays later.
Brian Wingert made his third field goal of the game, a 31-yarder, for Northern Iowa after Appalachian State's Trey Hennessee fumbled.
The Mountaineers briefly had a lead 7-6 after Richardson's 5-yard run in the beginning of the second quarter.
Wingert put the Panthers on the scoreboard first with a career-best 50-yarder on the opening drive and a 26-yarder after Appalachian State fumbled on its second kickoff return.
The game drew the largest crowd since it has been held in Chattanooga starting in 1997. Attendance was 20,236, about 430 fans short of a sellout.