My Entry for a contest. Here we have a rematch of the classic brawl from Crisis on Infinite Earths.
In one corner stands the Anti-Monitor, the scourge of the multi-verse and the big bad of Crisis on Infinite Earths. He's bringing the pain with his anti-matter waves, but now he must contend with one of the few beings able to hold her own against him in a one-on-one fight:
Kara Zor-El, i.e. Supergirl, who's sat upon the upper echelon of Earth's heroes ever since her debut in Action Comics. Let's not forget all of her subsequent re-introductions, reboots, and revivals in numerous Superman and Supergirl books since then (comic book continuity is confusing, isn't it?).
Supergirl/Kara Zor-El and the Anti-Monitor belong (c) to DC Comics