Scanlon recorded his second straight double-double and Mahoney only missed three of his 10 attempts from the field.
Javante McCoy scored 10 points off the bench for BU (11-12, 4-6 Patriot), which also snapped Bucknell's 15 game home winning streak earlier this season. Jonas Harper made his first career start and finished with four points and two steals.
Alex Vilarino scored on a contested layup in the closing seconds of the first half to extend BU's lead to 38-25. Scanlon had 10 points at the break.
Colgate, which never led, was within 67-64 with 4:18 remaining but didn't make another field goal.
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