Bridgewater led by as many as 10 points in the first half but Marietta pecked away at the lead and finally overcame the Eagles to lead 42-40 with 12:56 left in the game.
The Pioneers stretched the lead to 15 points with 8:38 left to play, but the Eagles battled back and with 1:00 left in the game, BC trailed by just one, 70-69, when Kris Cecil drained a 3-pointer.
Marietta missed on its next possession but the Pioneers controlled the offensive rebound, forcing the Eagles to foul.
Marietta’s Tyler Morando hit both free throws to make it a 3-point difference. Bridgewater had two shots to tie in the closing seconds but the Eagles were unable to convert.
Dominic Trawick led the Eagles (4-3) with 16 points while Josh Fox and Andrew Cathlin each finished with 11.
Marietta post man Matthew Rucker scored 22 points on 9-of-10 shooting to lead the Pioneers.
The Eagles will meet Olivet in the consolation game Wednesday afternoon.