The Wildcats (20-13) made 15 of 36 from 3-point range and tied a school record for wins that they set last year. They will play the winner of Monday night’s game between Oklahoma State and Washington State winner for the chance to reach the tournament’s final four.
Joe Trapani scored 18 and Josh Southern had 12 for BC (21-13), which ends its first season under coach Steve Donahue.
Northwestern, which has never been in the NCAA tournament, made the NIT for the third straight year and beat Wisconsin-Milwaukee 70-61 in the opening round. BC beat McNeese State 82-64 in the first round.
Donahue took his starters out with 1:21 left and BC trailing by 14, giving the crowd a chance to cheer for seniors Trapani, Southern, Biko Paris, Corey Raji and John Cahill.