EVANSTON, Ill. -- Nebraska committed two uncharacteristic turnovers Saturday night when knocking on the door for touchdowns, but the missed scores ultimately didn't matter.

Quarterback Tommy Armstrong Jr. threw for one touchdown and set up two others as the No. 20 Cornhuskers went on to claim a 24-13 victory over Northwestern in a Big Ten opener for both teams at Ryan Field.

"After being in a position to score two touchdowns and not getting any points, probably the best thing about that was that we came back and had to keep playing," Nebraska coach Mike Riley said. "It was probably really good for us, (but) I wouldn't want to do that every week."

The Cornhuskers (4-0, 1-0 Big Ten) came into the game averaging 43.3 points per game but produced their lowest point total of the season.

Armstrong was 18 of 29 for 246 yards and also rushed 13 times for a game- and career-high 132 yards.

"We want to be better and better as we go, but (Armstrong) had some good ones and some timely ones for sure, and a good mixture," Riley said.

Quarterback Clayton Thorson scored on a 42-yard run and combined with Austin Carr on a 24-yard touchdown pass for the Wildcats (1-3, 0-1). Running back Justin Jackson rushed for 84 yards on 20 carries and Carr had a career-high eight catches for 109 yards.

Thorson was 24 of 37 for 249 yards. He was sacked three times and intercepted with 1:23 left in regulation as Nebraska secured the win.

In the wake of Northwestern's third loss in four games, coach Pat Fitzgerald said it's time to reassess personnel.

"We're going to have to look at a lot of guys, we're going to have to look at a lot of their performances very hard and obviously play some more people," he said. "There's no more motivator to me than opportunity. You give guys opportunities to play and we'll continue to compete through practice and the best guys will start."

Nebraska built on a 10-7 halftime lead with its first drive of the second half. Armstrong set up a score with a 35-yard completion to Brandon Reilly at the Northwestern 8 and three plays later found Cethan Carter for a 4-yard scoring pass.

Northwestern replied with the Thorson-to-Carr touchdown strike but missed the extra point attempt as the Cornhuskers maintained a 17-13 lead with 7:29 left. Less than four minutes later, Jordan Westerkamp's 10-yard sweep helped Nebraska to a 24-13 advantage.

Nebraska piled up 556 yards to Northwestern's 388 and had a nearly 11- minute advantage in time of possession. Fitzgerald said the team practiced to counter the Cornhuskers' explosive attack and thought they were prepared.

"It's mind-boggling to me," he said. "We did it right all week in practice. I've got to look at why and we've got to come up with a plan and I've got to fix it."

The Cornhuskers produced plenty of yardage -- 285 net yards -- in the opening half but twice turned the ball over inside the Northwestern 1 before hitting paydirt late.

Cornhuskers running back Terrell Newby sprinted 49 yards on the opening drive and seemed destined for the game's first score. But Newby fumbled into the end zone and the ball bounced out of bounds to give Northwestern possession.

On their second drive, the Wildcats stalled inside the Cornhuskers' 10 and kicker Jack Mitchell missed a field goal try from the 27.

Nebraska opened the second quarter with a 27-yard pass from Armstrong to Carter to the Northwestern 8 but stalled and settled for a 23-yard Drew Brown field goal and a 3-0 lead.

The Wildcats took a 7-3 lead with 9:09 left in the half on Thorson's 42-yard run and his first rushing TD of the season.

The Cornhuskers were camped at the Wildcats' 2 with 3:24 to play in the second quarter after Armstrong's 37-yard sideline dash. But Devine Ozigbo fumbled at the 1 and Northwestern safety Godwin Igwebuike recovered in the end zone for the touchback.

Northwestern gave the ball back and this time Nebraska succeeded. The Cornhuskers knocked on the door after a 59-yard pass from Armstrong to Alonzo Moore. One play later, Newby rushed 4 yards for Nebraska's first touchdown and a 10-7 lead.

NOTES: Nebraska opened its sixth Big Ten season with a perfect (3-0) nonconference record for the second time in three years. ... Four of the last five meetings between the Cornhuskers and Wildcats hde been decided by three or fewer points coming into Saturday. ... Nebraska scored 30 or more points in eight games last year. Through three games this season Nebraska was ranked 17th nationally, averaging 43.3 points per game. The averaged dropped to 38.5 points after Saturday. ... Northwestern RB Justin Jackson moved into third place on the school's career rushing list but still has a long way to go to catch No. 2 Darnell Autry (1994-96) and his 3,793 yards. ... LB Jaylen Prater entered Saturday atop the Big Ten with 30 total tackles and added eight on Saturday. ... Northwestern travels to Iowa next week and Nebraska hosts Illinois.