The sophomore, who finished third in rushing in the SEC last year, punched in a 2-yard run just 58 seconds into the game and Mississippi State never looked back, building a 35-0 lead by the half.
Fitzgerald finished with 41 yards rushing, before exiting the game in the third quarter. Aeris Williams paced the Bulldogs, rushing 16 times for 83 yards with a 2-yard touchdown.
Dontavian Lee added a touchdown on the ground while Gabe Myles, Deddrick Thomas and Jamal Couch hauled in scoring grabs.
The Mississippi State defense, which struggled at times last season, was equally impressive as the offense. The Bulldogs held the Buccaneers to 33 total yards, including 14 yards in the second half.
The unit, under new defensive coordinator Todd Grantham, shut down the Buccaneers' potent running game, punctuating the win with two first-half safeties. For the day, Charleston Southern managed just one first down, punted 12 times and failed to get the ball past midfield.
Quarterback Shane Bucenell struggled mightily against the Bulldogs. The sophomore quarterback finished 3 of 8 for 15 yards. As team, Charleston Southern managed 18 yards on the ground.
Buccaneers safety Demetri Royer led all players with 12 tackles. Mississippi State's Jeffery Simmons earned the game's lone sack.
Mississippi State's 555 total yards marked the 19th time since 2014 that the Bulldogs have rung up more than 500 yards in a game. That's the most of any team in the SEC during that time frame.
The win was the largest margin of victory in the Dan Mullen era.