Weaver (21-9) jumped out of the gate quickly from the perimeter. The Bearcats connected on six 3-pointers in the first quarter, giving them a 21-12 advantage after one.
Piedmont (8-20) outscored the Bearcats 18-11 in the second quarter to cut its deficit to 32-30 at halftime. Spears and Darnell Jackson scored nine points apiece for the Bulldogs in the quarter.
Jackson finished with 15 points and five rebounds for Piedmont.
Weaver closed out the game on a 36-23 run in the second half.
Both teams advance to the sub-regional round. The Bulldogs travel on Friday to Area 9 winner Ashville (18-11), a 44-40 winner over Glencoe (19-10) in other area tournament final action on Monday. Weaver will host Glencoe, also on Friday at 7 p.m.