In the scene in The Avengers after Loki is captured, Cap and Stark are quietly wondering why the "Rock of ages" is giving up so easily. Cap says he recalls that that Loki packs a wallop. What is he referring to? When did Cap ever encounter Loki?
Captain America is the first one to fight Loki in the Avengers movie. When Loki tries to subjugate the people by making them Kneel, Captain America comes to the calling first before Iron man shows up which leads to Loki surrendering easily.