The Seminoles added their second field goal of the game a series later.
Notre Dame punted on its next possession, but pinned FSU inside its own 5 and forced a quick three-and-out.
A poor punt by the Seminoles and a facemask penalty on the return gave the Irish the ball on the FSU 28 with 3:56 to play, but Rees was picked off in the end zone with 2:48 left and FSU was able run out most of the remaining time.
Notre Dame took a 14-0 lead on its opening drive of the second half by capping a nine-play, 62-yard drive with a 5-yard touchdown pass from Rees to Floyd. Floyd fought Seminoles cornerback Greg Reid for the ball on to play, juggling it multiple times before finally getting his hands around it.
Reid stayed down on the turf after the play and left the game with concussion symptoms.
FSU bounced right back with a 77-yard kickoff return by Lamarcus Joyner, but Notre Dame's fifth sack of the night on Manuel helped force the Seminoles to settle for a 42-yard field goal by Hopkins.
Safety Terrance Brooks, who had a late interception to help seal the win, said belief in themselves is the biggest thing they will carry into next season.
"Just go out there and do it," he said. "You know you've got it in you. We went out there and read our keys and got the job done."