Illinois State defeated Southern Illinois in its first Missouri Valley Conference game, 4-1 from Normal.
Brent Headrick and Colton Johnson faced just five batters over the minimum in the victory. Headrick fired seven, one-run innings allowing two walks and struck out four.
Derek Parola finished 2-for-4 with a solo home run. Joe Butler and Nick Zouras drove in runs for ISU as well.
The Redbirds (33-22) will play the winner of Evansville and Indiana State tomorrow at 7 p.m.