Who wins?
Bruce Wayne: He has not been trained, has not become The Dark Knight yet.
Kal-El: There is a Red Star, and is surrounded by Kryptonite.
No weapons. No preparation time. Spontaneous show down.
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Kal-El keeps his abilities while under a red sun, but he constantly loses energy to use them. Thus, he could still punch Bruce's head off before he loses his powers, even if he's in extreme pain from the kryptonite as he does it.