A lock assembly includes an exterior operator assembly having an exterior operator handle. An interior operator assembly has an interior operator handle having a mounting opening. An outer spindle is operatively coupled to a latch assembly, drivably coupled to the interior operator assembly, has a longitudinal bore, and is rotatable about a first axis. A coupling mechanism is drivably coupled to the outer spindle. A locking spindle assembly is rotatably received in the longitudinal bore and rotatable about the first axis, and is configured to selectively operate the coupling mechanism to drivably couple the exterior operator assembly to the outer spindle. A motor drive assembly includes a motor having a motor shaft. The motor is positioned inside the mounting opening of the interior operator handle. The motor shaft is drivably coupled to the locking spindle assembly to operate the coupling mechanism when the motor drive assembly is actuated.