NORMAL, Ill. -- Luther Kirk returned an interception 39 yards for a touchdown in the fourth quarter and Illinois State pulled away for a 33-16 victory over Western Illinois in Missouri Valley Football Conference play on Saturday.

Kirk's interception return was sandwiched around two James Robinson TD runs in the final quarter as the Redbirds (4-1, 1-1), ranked 14th in the FCS coaches' poll, erased a 16-12 deficit.

Sean McGuire had two TD passes in the first half for the Leathernecks (2-3, 1-1) -- a 16-yarder to Tony Tate and a 35-yarder to Steve McShane with 60 seconds left in the second quarter for a 13-12 halftime lead. Western Illinois upped its advantage to four points on Sam Crosa's 21-yard third-quarter field goal.

But the fourth quarter was all Illinois State. Robinson scored on an 11-yard run to cap a six-play 52-yard drive that gave the Redbirds a 19-16 lead. Kirk's pick-6 stretched the lead to 10 points and Robinson added a 2-yard TD run to cap the scoring. Kirk's interception was the ninth already for Illinois State, matching its total of last season.

McGuire, coming off back-to-back 300-yard passing games, completed just 14 of 35 for 220 yards.

Robinson finished with 145 yards rushing and three TDs on 29 carries.