Evans put the Huskers up 21-3 with the first of his two interceptions, catching a ball tipped by Tyre'oune Holmes and going 22 yards to the end zone.
It was a solid rebound for a Nebraska defense that surrendered 602 yards in a 37-34 win over Wyoming last week.
The Golden Eagles (0-2) lost their 14th straight, the longest losing streak in the FBS.
Abdullah went over 100 yards for the second straight game, finishing with 114 on 17 carries, and the Huskers generated 285 yards on the ground.
The Huskers finished off the Golden Eagles after Bridgford's 41-yard touchdown pass to Bradley made it 35-13 early in the third quarter.
Kenny Bell ran back the kickoff 63 yards, and Abdullah scored from 37 yards on the next play.
Evans intercepted Bridgford on the first play of Southern Miss' following possession, and Martinez threw a 26-yard touchdown pass to Sam Burtch to make it 49-13.
Nebraska's two interception returns for touchdowns marked the first time the Huskers have had two defensive scores in a game since they had two picks for TDs against Idaho in 2010.
Jean-Baptiste was recruited as a receiver and switched to cornerback early his sophomore season. It's been a good move. The senior has two interceptions in two games and five for his career. Last year he ran back a pick for a TD against Minnesota.
Evans also has two picks this season, and the touchdown was his first since he ran back an interception against Idaho State last year.
Nebraska's defense needed a boost of confidence after Wyoming skewered it for 28 plays of 10 yards or longer last week. The Huskers tinkered with the lineup, starting junior-college transfer Randy Gregory at end, freshman Josh Banderas at middle linebacker and Nathan Gerry as an extra defensive back in the dime package. Nebraska hadn't started a true freshman on defense since Evans in 2010.
Southern Miss totaled 132 yards in the first quarter and had a touchdown erased by a penalty. The Huskers limited the Eagles to 94 yards over the second and third quarters and began substituting in the fourth.
Bridgford, who threw for 377 yards last week in a loss to Texas State, was 21 of 35 for 222 yards. But Bridgford and the Eagles, who turned over the ball six times last week, couldn't overcome the four interceptions - the last one thrown by Nick Mullens.
The schedule originally called for Southern Miss to host the Huskers in Hattiesburg, Miss., but the Eagles agreed to move the game to Lincoln in exchange for $2.1 million. The teams play again in Lincoln in 20
*** Bryan Munson contributed to this report ***