LINCOLN, Neb. - Michigan State's first loss of the season won't come without controversy.

Tough-luck Nebraska, quite frankly, doesn't care.

Quarterback Tommy Armstrong threw a 30-yard touchdown pass to wide receiver Brandon Reilly with 17 seconds remaining as Nebraska rallied from a 12-point deficit to defeat No. 7 Michigan State 39-38 on Saturday night at Memorial Stadium.

On a drive that started at Nebraska's 9-yard line with 1:02 remaining, Armstrong completed passes of 33 and 28 yards to Jordan Westerkamp to get Nebraska in position for the winning score.

Reilly came out of bounds at the 3-yard line to catch the ball, but officials ruled he was forced out, therefore making the catch legal. Replay reviews upheld the call.

"I got an explanation. They said that the receiver was pushed out of bounds," Michigan State coach Mark Dantonio said. "Everybody saw the replay. I'm not qualified for that job. My job is to coach and I'm going to do the very best I can. That's somebody else's job."

Armstrong finished 19 of 33 passing for 320 yards and two touchdowns as Nebraska (4-6, 2-4 Big Ten Conference) kept alive its slim bowl hopes, and ended Michigan State's 12-game Big Ten Conference road winning streak and likely its national championship hopes in the process.

Nebraska, coming off an embarrassing 55-45 loss at Purdue, had lost five games this season, the first for coach Mike Riley, by a combined 13 points. Four of those came on the opponent's final offensive snap, including a 'Hail Mary' pass in a loss to BYU to begin the season.

This time, though, the Huskers celebrated when Michigan State quarterback Connor Cook's pass from the Nebraska 41-yard line fell incomplete.

"Well, I guess we found out it's not over 'til it's over," Riley said. "I'm really thrilled for these players and our coaching staff. I think that besides winning the game, which is the key to everything, I suppose, I just think the fact that everybody, the coaches, the players kept working so we could get to this point and win this game.

"When you go through a stretch like we have, one of the things that you fear the most is that people lose hope, stop working, kind of start losing that identity."

Cook threw for 335 yards and four touchdowns for the Spartans (8-1, 4-1). Cook, 23 of 37 for the game, completed seven passes for 125 yards on two third-quarter touchdown drives that seemingly put Michigan State in control.

The Spartans had only five second-half drives, but the first three resulted in touchdowns, the last a 1-yard scoring run by Gerald Holmes for a 38-26 lead. That finished a mammoth 16-play, 75-yard drive that lasted 8 minutes and 50 seconds, and left only 4:16 remaining in the game.

Nebraska rallied behind Armstrong's 4-yard TD run with 1:47 remaining. Then the Huskers, with the help of two timeouts and a Michigan State penalty, forced a punt to regain possession for its winning drive.

"Everybody is going to take responsibility for this," Dantonio said. "I can tell you that our offense will take responsibility, the coaches will take responsibility, the defense will take responsibility, and every individual player will, so there's plenty to go around. With that being said you have to credit the people we played against and I didn't think the officiating lost us the game."

Michigan State trailed 10-0 but took a 17-13 halftime lead on Cook's 18-yard touchdown pass to Macgarrett Kings with 17 seconds remaining in the second quarter.

That capped a 10-play, 75-yard drive that began after Drew Brown's 43-yard field goal had given Nebraska a 13-10 lead.

Nebraska started strong, holding Michigan State on fourth-and-short from the Nebraska 23-yard line on the opening drive of the game. Two possessions later, the Huskers went 38 yards in nine plays and settled for a 44-yard field goal from Brown for a 3-0 lead.

Nebraska forced a three-and-out to regain possession, and Armstrong connected with Westerkamp on a 38-yard touchdown pass for a 10-0 advantage.

Michael Geiger made a 46-yard field goal for Michigan State, and the Spartans tied the game when Kings caught a short pass from Cook, cut back and raced untouched for a 34-yard touchdown.

NOTES: Nebraska played an undefeated team at home in the month of the November for the first time since 1999, when the seventh-ranked Cornhuskers defeated No. 5 Kansas State 41-15. ... As a ranked team, Michigan State had lost only once in 36 games to an unranked opponent (at Notre Dame, 2011) before Saturday. ... Nebraska played its first ranked opponent of the season.