Almost everytime Superman and Wonder Woman fight, he outstats her.
Every time Wonder Woman and Supergirl fight, the Amazon destroys her on skill.
Logically, Superman should do better against Supergirl. But he doesn't.
So yeah, who wins?
__________________ What CDTM believes;
Never let anyone else define you. Don't be a jerk just to be a jerk, but if you are expressing your true inner feelings and beliefs, or at least trying to express that inner child, and everyone gets pissed off about it, never NEVER apologize for it. Let them think what they want, let them define you in their narrow little minds while they suppress every last piece of them just to keep a friend that never liked them for themselves in the first place.
Diana slits superdouche's throat with he MAGIC tiara, blocks all of Supergirl's attacks with her MAGIC shield, ties her up with her MAGIC lasso, and then eviscerates her with her MAGIC sword.
Supergirl is not, on the whole, portrayed as being as powerful, much less more powerful than Superman.
It's a cheap trick to draw attention to Supergirl; one that recurs but rarely sticks. What is strange is that Supergirl almost never shows the same level of dynamism in her power levels that Superman does.