The Terps saw their six-game winning streak snapped.
Ben Cowles' four-RBI performance lifted the Terps to their fourth straight victory.
Strong performances from Nick Dean and Logan Ott pushed the Terps to victories over Iowa and Northwestern.
Luke Shliger drew a bases-loaded walk in the 10th inning to give the Terps a victory.
The Terps recorded 13 hits as a late surge carried them past the Cornhuskers.
Costes knocked the go-ahead, two-run single in the sixth inning as the Terps picked up their third straight win.
Jason Savacool and Connor Staine are among the starters set to take the mound over the weekend.
The Terps fall to 5-9 with their losses on Sunday.
The Chanticleers put up seven runs combined in the seventh and eighth innings.
A costly error in the seventh inning by left fielder Troy Schreffler helped the Rams pull away.