Captain America, Vol. 3 #7A (1998)

Power and Glory, Chapter Three: Hoaxed
Cap rallies the Avengers to contain the rioting caused by the Skrull imposter, but he does so out of uniform. By keeping the mask off, he forces the Skrull imposter to come forth, at which time he is exposed by Tony Stark and Reed Richards, who build a device that will temporarily revert him to his true form. Exposed in a press conference, Cap defeats him in battle, and explains the situation to all of the press present.
Release Date: 1998