Kessler completed 22-of-31 attempts and connected twice each with Marqise Lee and Nelson Agholor on scoring strikes for the Trojans (10-4), who won seven of their final eight games after the September firing of head Coach Lane Kiffin.
Six of the wins came under interim Coach Ed Orgeron, who resigned after being passed over in favor of Steve Sarkisian for the permanent job.
Offensive Coordinator Clay Helton guided the Trojans to Saturday's victory.
Lee finished with 118 yards on seven catches and Javorius Allen added a pair of rushing touchdowns for USC.
National passing leader Derek Carr was held to 217 yards and two touchdowns with an interception on 29-of-54 efficiency for the Bulldogs (11-2), who finished the season with two losses in three games.