Quinnipiac's Ousmane Drame converted a three-point play to give the Bobcats a 51-49 lead with 2:25 to play. Teddy Okereafor and Lopez made back-to-back layups to make 53-51 at the 1:04 mark. Okereafor made a pair of free throws, and the Bobcats' Ayron Hutton answered with a layup to make it 55-53.
After Zedric Sadler split a pair of free throws, Okereafor forced a turnover and grabbed a late offensive rebound to seal it for Rider (11-7, 5-2 Metro Atlantic).
Lopez had nine rebounds, Sadler scored 11 points and Okereafor chipped in seven.
James Ford Jr. scored 17 points on 7-of-20 shooting, and Drame had 15 points, 11 rebounds and five blocks to lead Quinnipiac (8-8, 2-5).