The Terps were held to four hits in the season-ending defeat.
The Terps cruised to a victory after scoring three runs in the opening inning and will play the winner of San José State and BYU on Friday.
The Terps' pitching struggles led them to an exit in the opening round of the conference tournament.
The Terps won 36 games this season, the most since 2012.
Courtney Wyche limited the Fighting Illini's offense throughout the Terps' crucial win.
Courtney Wyche and Trinity Schlotterbeck combined to strike out 11 and only allowed three runs across the two games.
The Terps gave up two runs in the sixth inning and failed to score apart from Ameila Lech's one-run homer in the third inning.
The Terps were 1-of-9 with runners in scoring position in the loss.
The Terps left multiple runners in scoring position in the loss.