LINCOLN, Neb. (AP) -Roy Helu Jr. was getting better for No. 24 Nebraska as the game went on, and by the third quarter he was nearly unstoppable.

With Helu running for two of his three touchdowns and 95 of his 152 yards in the quarter, the Cornhuskers broke open the game and went on to a 49-3 victory over Florida Atlantic on Saturday night.

Helu put to rest any concerns about hamstring problems that bothered him last season and in preseason practices. He also showed he's quite capable of being the Huskers' featured back in the wake of Quentin Castille 's dismissal for breaking team rules.

''In the first quarter I was impatient with my reads,'' Helu said. ''The feeling was good in the third quarter. The type of offense we're trying to become, you saw it in the third quarter.''

If Helu keeps running like he did against the Owls, it will make things much easier for quarterback Zac Lee .

Lee took his most meaningful snaps since 2006, his last year of junior college, and passed for 213 yards and two touchdowns in his first start.

Lee got sharper after a fumbled snap led to a three-and-out on Nebraska's first series. He threw touchdown passes of 28 yards to Menelik Holt and 49 yards to Curenski Gilleylen and led a 15-play, 82-yard drive that Helu finished with a 1-yard run.

''There was a little bit of anxiety, but that faded pretty quickly,'' Lee said. ''Once you throw a couple passes, it's back to playing football.''

The Huskers opened Bo Pelini's second season as head coach with the program's 24th straight win in an opener, the longest streak in the nation.

''You play that first game, and it gives you a benchmark, an idea where you are,'' Pelini said. ''I saw some good things out there. We got to play a lot of guys. But I also found out we have a lot of work to do. We were sloppy at times and not real crisp.''

The Huskers were at their best in the third quarter, thanks to a defense that forced three turnovers by FAU's Rusty Smith .

Smith, the Sun Belt Conference's all-time leading passer and the preseason offensive player of the year, couldn't establish any rhythm. He was intercepted by Matt O'Hanlon and Prince Amukamara , and he fumbled a snap.

''I'm sure they went into halftime concerned about how they looked against us,'' FAU coach Howard Schnellenberger said. ''They put it into overdrive, and I asked our guys to put it into overdrive, but we didn't have enough juice in the tank. It's a very bitter loss for us. It's the first one that I've had with this program that is tougher to handle than others because I expected more out of this football team that what I got at this juncture.''

Helu uncorked his run of the night on a 44-yard touchdown, cutting back after starting to his left and breaking out of the grasp of FAU safety Rod Huggins .

''That's Roy - great player, great runner,'' Lee said. ''The thing we saw tonight was how strong he is, breaking tackles, making moves. He's going to be that guy for us. We're going to rely on him and get him the ball.''

Over the past five regular-season games, Helu has rushed for 662 yards on 86 carries, an average of 7.7 yards.

Helu, who went over 100 yards for the fourth time in six games, also had a 7-yard TD run in the third, when Nebraska rolled up 185 of its 490 yards.

Lee completed 15 of 22 passes, with one interception, before giving way to freshman backup Cody Green early in the fourth. Green ripped off a 49-yard run before scoring Nebraska's last TD from a yard out.

The game also marked the much-awaited debut of freshman Rex Burkhead , who ran for 39 yards and an 8-yard touchdown.

Alfred Morris led the Owls with 85 yards.

The Owls' 3 points were the fewest against Nebraska since the Huskers' 21-3 win over Kansas State in 2006 and the fewest in a Nebraska opener since 1994.

Nose tackle Ndamukong Suh said the defense was in midseason form with one exception. The Huskers allowed 122 yards rushing.

''Rate our defense? B-minus,'' Suh said. ''There were a couple breakdowns, and that let them get some momentum. When we're point on, we're getting three-and-outs. There were some lax places that we need to clean up.''