Coprich's 83-yard romp-the longest of his career- with 5:40 remaining sealed the win for the Redbirds (6-1, 4-0 Missouri Valley Conference). Coprich might have scored again earlier in the fourth, but the Leathernecks' Brett Taylor forced him to fumble at the goal line. The ball bounced directly into the hands of Illinois State's Anthony Warrum in the end zone for the score.
Warrum finished with 170 yards receiving on four catches and a receiving touchdown.
Western Illinois (4-3, 3-1) led once when Devon Moore ran for a 10-yard score to put the Leathernecks up 28-21 with 8:25 left in the third quarter.
Tre Roberson threw for 211 yards, two touchdowns and two interceptions for the Redbirds.
The Leathernecks' Trenton Norvell was 27 of 47 for 313 yards passing with two touchdowns.