Grambling State (3-2, 3-0 Southwestern Athletic) led 28-20 at halftime, but scored 21 unanswered points in the fourth quarter after Jackson State (1-4, 1-2) had closed to 38-27.
Williams threw scoring passes to Brandon Byrdsong, Chris Bazile, Ka'Jandre Domino and Chester Rogers. Martez Carter rushed for 97 yards and a touchdown. Jestin Kelly and Dre' Fusilier also scored. Marc Orozco added a 29-yard field goal.
Ivy La Montiez completed 40-of-58 passes for 490 yards and three touchdowns for Jackson State (1-4, 1-2), which stayed close into the third quarter. Jackson's last four drives ended in a punt, a missed field goal, an interception and the final whistle.
Jackson's Hector Stanback was taken off the field by stretcher, and is said to have suffered concussion-like symptoms with neck and back pain.