NU fell by a 71-66 margin in Bloomington, letting another chance for a key victory slip away.
Senior forward John Shurna, the Big Ten's leading scorer, posted 29 points, and carried the Wildcats through much of the second half.
The Wildcats and Hoosiers were nearly even in field goal percentage throughout the contest. The difference was in the second half, where an exhausted Northwestern team was unable to match Indiana as it took control. NU received one point off the bench, a Jershon Cobb free throw in the first half.
NU's record now sits at 15-10 overall, and 5-8 in Big Ten play. Each possession and point will be critical for its fading tournament hopes.
Next up for Northwestern is Minnesota, who travels to Welsh-Ryan Arena on Saturday night.