Austin Peay (2-1) has now won two straight under first-year coach Mark Hudspeth.
Each team kicked two first-half field goals and the game was deadlocked at intermission, 13-13.
JaVaughn Craig, who finished 18 of 32 for 252 yards, opened the second with a five-yard strike to Baniko Henry to put the Governors on top for good, 20-13 and Jackson pushed to 27-13 with his first pick six, this one from 29 yards out.
Robert Riddle got the Bears within a touchdown with a 4-yard pass to Chris Ellington to cut the Mercer (2-1) deficit to 27-20, but Austin Peay opened the fourth quarter with a touchdown run by Williams from three-yards out and a 69-yard pick six by Jackson that pushed the lead to 41-20.
Mercer's Riddle finished 29 of 47 for 287 yards and four touchdowns, but his two interceptions resulted in 14 Austin Peay points.
Wyoming football recruit Tony Evans Jr. killed in shooting at Dallas hotel, police say
Wyoming football recruit Tony Evans Jr. was killed early Sunday in a shooting at a Dallas hotel, according to police.
What Titans legend Eddie George is bringing to Tennessee State
Turron Davenport reports on Tennessee State hiring former Titans RB Eddie George as its new football coach.
Sources: Former Tennessee Titans star Eddie George named Tennessee State Tigers coach
Tennessee State is hiring Eddie George to be the Tigers' new head coach, sources told ESPN's Adam Rittenberg. George starred at running back for the Tennessee Titans.
The highlights that make Kyle Pitts the most electrifying player in the draft
Kyle Pitts looks to take the NFL by storm by being a versatile pass catcher and one of the most dynamic players in the draft.
Northwestern St. wins wild finish 49-47 over Incarnate Word
— Eddie Godina kicked a 32-yard field goal on the final play and Northwestern State won its first game of the spring season in its season finale 49-47 over Incarnate Word on Saturday night.
Coach Prime sends a player off after late penalty
Jackson State's Aubrey Miller Jr. commits an unnecessary penalty on an Alabama A&M kneeldown. Deion Sanders is not pleased and sends him to the locker room early.