Captain AmericavsSuperman

Captain America is the moral center of the Marvel Universe and arguably its greatest fighter pound-for-pound. But Superman is... Superman. This is a case where heart, skill, and determination simply cannot overcome the physics of fighting a solar-powered alien god.

Superman can move at lightspeed, lift planets, survive supernovae, and project energy hot enough to rival stars. Captain America is a peak-human super-soldier who can bench about 1,200 pounds. The gap between these two is like the gap between a skilled martial artist and a nuclear weapon.

Cap's vibranium shield is the only thing that makes this even slightly interesting. It can theoretically absorb any amount of kinetic energy, meaning Superman's punches wouldn't shatter it. But Superman has options that don't involve punching the shield — heat vision, freeze breath, simply flying Cap into space.

In the comics, Cap has faced god-tier opponents before and his courage never wavers. Superman would respect that enormously. But respecting your opponent doesn't change the outcome.