After a four-hour delay due to poor weather, Omaha found itself in a back-and-forth affair on Saturday.
The Mavericks held leads of 1-0, 3-2 and 5-4 against Valparaiso before falling 7-5 at Tal Anderson Field.
The Beacons scored the game's final three runs to improve to 7-5 on the season. Omaha is now 3-9.
Mike Boeve and
Eddie Satisky each had three hits for the Mavericks, who outhit Valpo 12-9 in the loss.
Noah Greise gave Omaha its final lead with a two-run double in the bottom of the sixth inning.
Adam Brauch's two-run double in the seventh off losing pitcher
Tanner Howe (0-2) put Valpo up to stay.
Charlie Riedel got the start for the Mavericks and pitched two scoreless innings.
Jarrett Blunt, Howe and
Wyatt Sellers combined to pitch the final seven innings, with each giving up at least one run in the game.
Omaha claimed a 1-0 lead in the second when
Harrison Denk drew a bases-loaded walk.
Eduardo Rosario and Satisky drove in runs in the fifth inning to reclaim a 3-2 lead for the Mavericks.
Kyle Schmack and Spencer Warfield each had three hits for Valpo.
Nathan Chasey (1-1) picked up the win in relief for the Beacons.