Justice League of America #56

The JLA and JSA team up to stop the Black-Sphered Villains on Earth-2, using artificial means to power up four of their own with black matter, but it almost backfires when the four heroes become evil. The remaining heroes are then subconsciously helped by the four heroes into defeating them by exposing their weaknessses. These same weaknesses are then used vs. the four earlier-charged normal persons, who then lose their powers as well. Things are returned to normal on Earth-2, and the four Leaguers return to their world to stop the charged persons there using the same weaknesses.