Action Comics #424 pg 13

Superman reveals that he knew Grodd's mental powers were holding him back in the fight so he pretended to be knocked out to give him time to figure out a solution. But when Solovar stepped in and defeated Grodd with no resistance, he concluded that Grodd had taken over Solovar's body. Superman takes Grodd and Solovar, both still unconscious, back to Gorilla City to return their minds to their proper place. Once recovered, Solovar confirms Superman's theory explaining that Grodd initially overpowered Solovar while he was distracted by Gorilla City being exposed, and Grodd was still controlling Solovar even when his mind was in Grodd's body. Grodd's goal was to appear as a superhero to eventually take over the world legally.

Originally published June 1973