The Gators were hanging onto a 30-24 lead and Penn State was driving for a go-ahead score with 1:11 left when Black collected the fifth interception of the game for Florida, running it back 80 yards to ice the game.
The victory for Florida (8-5) enabled Coach Urban Meyer to leave the Gators after six years at the helm with an exciting win over another coach with two national championships, Penn State's Joe Paterno.
Meyer had announced he was stepping down due to family reasons while Paterno, 84, has said he intends to return for a 46th season with the Nittany Lions.
Jordan Reed tossed for 61 yards, adding 70 more on the ground, and John Brantley completed 6-of-13 passes for 41 yards for Florida, while Omarius Hines added a rushing TD.
Penn State (7-6) got a spotty performance from Matt McGloin, who threw for a touchdown and ran in another but was intercepted five times.