Quinnipiac (15-13, 9-10 Metro Atlantic) took its first 20-point lead at 52-32 and led by as many as 23. Siena got no closer than 15 points until closing the game with a 7-0 run.
Ousmane Drame had 11 points and 16 rebounds, and Justin Harris added 15 points and nine boards. Each had four blocks for the Bobcats, who shot 27 for 31 from the foul line.
Marquis Wright had 14 points, nine rebounds, seven assists and four steals while Evan Hymes scored 20 to lead the Saints (10-18, 7-12).
Siena opened the game with a 10-7 lead before Quinnipiac went in front for good with 18 straight points. Justin Harris' free throws at the 8:18 mark capped the Bobcats run at 25-10.