The win gave coach Bob Hoffman his 600th career victory.
Ross Cummings chipped in 10 points and Fardaws Aimaq grabbed 10 rebounds while scoring nine points.
Mercer (3-2) led 15-2 with 12:12 left in the first half. The Bears continued the damage, taking a 43-14 lead into the break.
AJ Cheeseman and Montraz Oliver had consecutive layups to start the second half as the Hawks opened with an 11-0 run to close to 45-25. Peavy nailed a 3 to halt the attack as Mercer answered with a 19-6 run to go up 64-31 with 6:49 remaining in the game and cruised to the win.
Oliver had 13 points and Bryan Urrutia added 12 points with four steals for the UMES (0-5).