The Jaguars built a 21-0 lead in the first quarter and ballooned the lead to 41-8 by intermission.
Southern (5-4, 5-2 SWAC) had a decided advantage in both total yards (483-188) and in time of possession (35:44 to 24:16).
Howard completed 15 of 21 passes for 229 yards and threw three of his touchdown passes in the first quarter - including 37-yard strike to Malcom Crocket.
Tillery added 111 yards on 14 carries. Malcom Crockett carried 22 times for 107 yards and a touchdown as the Jaguars amassed 254 yards rushing.