Vermont (18-9), of the America East Conference, made 27 of 31 free throws to 12 of 14 for the Golden Griffins (17-11), of the Metro Atlantic Athletic Conference.
The Catamounts were 9 of 9 from the line in the final 3 minutes of the first half and led 38-30 after closing the half with a 14-3 run.
They never led by fewer than five points in the second half, when O’Day, a freshman, scored 14 of his points.
Harold Washington scored 27 points to lead Canisius, which came in averaging 9.2 3-pointers per game. They made 11 of 27, but Vermont was more efficient, making 8 of 16.
Clancy Rugg and Trey Blue scored 17 points each for Vermont, and Luke Apfeld added 14.