MMU took down Rice in a Saturday showdown at Virtue Field.
The Cougars clamped down in the second half to capture a 16-8 victory.
Mt. Mansfield improved to 6-2, while Rice fell to 2-6.
Elsewhere in Chittenden County, Vergennes met Milton on the baseball diamon.
The Yellow Jackets jumped out to an early lead and held off the Commodores to win 5-4.