Diaco shifted into a wildcat formation at the Fordham 4, took the snap and started toward the line before throwing to the back of the end zone where Michael Kane gathered in the tipped pass for a 14-10 lead with 13 seconds left in the first half.
Andrew Mevis' second field goal of the game cut the Raiders' lead to one before Grant Breneman threw 23 yards to Diaco for a 21-13 lead with just over four minutes left in the third quarter.
Breneman was 15-of-28 passing for 195 yards and rushed 16 times for 105.
The Raiders (3-8, 2-3 Patriot Football League) won their first home game this season after four losses.
Ryan Greenhagen had 19 tackles, nine solo, for the Rams (3-7, 1-3), who have lost three straight.
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