Lesnar and Heyman returned on the September 17 episode of "SmackDown" to challenge Kofi Kingston for the WWE Championship. Kingston accepted and Lesnar proceeded to "F-5" him. On "SmackDown"s 20th Anniversary on October 4, Lesnar quickly defeated Kingston to win his fifth WWE Championship; this was Lesnar's first match on "SmackDown" in 15 years. After his victory, Lesnar was attacked by former UFC opponent Cain Velasquez, making his WWE debut. Lesnar was then scheduled to defend the WWE Championship against Velasquez at Crown Jewel on October 31. During the 2019 draft, Lesnar was drafted to SmackDown. At the Crown Jewel event, Lesnar defeated Velasquez in under five minutes via submission with the Kimura Lock. After the match, Rey Mysterio attacked Lesnar with a chair. On the November 1 episode of "SmackDown", Lesnar and Heyman quit the brand in order to go after Mysterio, who had been drafted to Raw, thus transferring to Raw with the WWE Championship. This led to Mysterio challenging Lesnar for the championship at Survivor Series, which was made official as a No Holds Barred match, where Lesnar retained, despite Dominic's attempt to aid Mysterio during the match.