The senior wide receiver went out on a high note at Williams-Brice Stadium, catching three passes for 53 yards, including a 29-yard touchdown reception in the first quarter.
The senior safety capped his home career with a 21-yard interception return for a touchdown in the second quarter. He also added one later in the same quarter.
Although the USC defense gave up a few chucks of yardage in the first half, it did stiffen inside the 20-yard line by holding the Jaguars to four field goals.
After picking off only five passes in the first 10 games of the season, the Gamecocks collected four against South Alabama quarterback Hunter Vaughn. Linebacker Skai Moore, who led the team with nine tackles, had the other two interceptions.
The sophomore kicker booted three field goals, including a career-long 47-yarder in the third quarter.
The senior quarterback finished his USC playing days at home by catching the first touchdown pass of his career, a 7-yarder from Pharoh Cooper. Thompson also threw for 237 yards to pass 3,000 for the season.
Despite a beautiful Saturday afternoon, many fans stayed away for the final home game of the season, as scores of empty seats littered the upper decks.
The senior tight end dropped a pair of passes on USC's opening drive, including one in the end zone that led to a field goal. He also picked an unsportsmanlike penalty in the third quarter.
The Gamecocks lost four fumbles -- two by Mike Davis and one each by David Williams and Nick Jones -- and had a pass by Dylan Thompson intercepted.
The two fumbles limited his playing time, and the junior tailback finished the day with 13 yards on one carry.