Martinez went 15-of-23 through the air for 170 yards, hooking up with Sam Burtch, Quincy Enunwa and Kenny Bell on TD tosses for the Cornhuskers (2-0), who amassed 479 yards of total offense.
Ameer Abdullah led Nebraska's ground game, compiling 114 yards on 17 rushes with two touchdowns.
Allan Bridgford was victimized by three interceptions for Southern Miss (0-2), completing 21-of-35 for 222 yards and a touchdown.
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