Rector trailed 7-1 through four innings, but saw the 'Hounds plate five runs in the frame to move ahead 12-1.
The Cougars responded in their half of the fifth, with Mitchell Weber and Denver Knight driving in a run apiece. Rector added two more runs in the sixth, but Marmaduke's Cody Taylor put the icing on the cake with a base-clearing double in the final frame.
Knight took the loss on the mound for the Cougars.
Knight finished with a double, a single and an RBI. Weber notched two singles and an RBI. Dillon Shelton, Jake Scott, Dustin Sparks and Daniel White added a hit each on the afternoon.