Watch: Lesnar's WWE return spoiled by Orton's RKO

Brock Lesnar's return to the WWE amid failed drug tests following his latest UFC victory over Mark Hunt was not exactly what "The Beast Incarnate" had in mind.

During a Paul Heyman tirade on "Monday Night Raw" in which Lesnar's manager claimed SummerSlam opponent Randy Orton would never land an RKO on his client, Orton appeared out of nowhere and executed his famous finisher on Lesnar.

Lesnar and Orton battle at SummerSlam on Aug. 21.