With 3,743 yards, Coprich became Illinois State's career rushing leader, breaking Toby Davis' mark of 3,704 yards.
The Redbirds (2-1, 1-0 Missouri Valley Conference) never trailed. Coprich scored Illinois State's first two touchdowns to give it a 14-0 lead. Aaron Bailey connected with Michael Malloy on a 45-yard pass play to make it 14-7.
Illinois State responded with a three-play, 75-yard drive capped by Jamal Towns' 10-yard run to make it 21-7 before halftime. Coprich, averaging 127 yards per game, had a 61-yard run on the drive to set up the score.
Bailey was 7 for 17 with 108 yards passing with one touchdown and two interceptions for Northern Iowa (2-2, 0-1). Tyvis Smith had 14 carries for 54 yards.