The Bonnies (2-1) scored 22 points off of 19 Binghamton turnovers and scored 34 points in the paint.
Andrew Nicholson tallied 11 rebounds for St. Bonaventure, which outrebounded the Bearcats (1-2) 43-24.
With the game tied at 11-all with 11:22 left in the first half, the Bonnies outscored Binghamton 21-6 the rest of the half.
Leonard Lewis gave the Bonnies their largest lead of the game, 62-29 on a jump shot with 5:07 left to play.
St. Bonaventure shot 43.1 percent from the floor (25 of 58), compared to 38.6 percent shooting (17 of 44) by the Bearcats.
Binghamton was led by Chretien Lukusa with 12 points.