Italy's backcourt reigned supreme as guards Simona Ballardini and Raffaella Masciadri scored 18 points each in the win.
Masciadri made six of 10 from the field, including three of four from beyond the arc.
After a tight first quarter, Italy pulled away before half-time and took a 40-32 advantage into the locker rooms.
Laurence Val Malderen led Belgium with 15 points while Sara Leemans had 13 and Jana Raman had 10.
The win leaves Italy at 3-0 going into their final game against Croatia on Monday.
The result eliminates Belgium and makes Monday's clash between Italy and Croatia a dead rubber.