What Esteemed said. Nobody's arguing Wonder Woman with her normal abilities can't rock Lady Shiva's world. Take those away, though, and leave her with only skill to fall back on ... and I'm not so sure she'd beat Shiva.
Now intuitively, it would seem that Wonder Woman ought to be able to because she's been fighting since long before Shiva's parents ever even MET and is therefore far more experienced ... but we know how much that counts for most of the time in comics. 😉
And then, too, in all fairness, it could easily be said that there are dimishing returns -- that you can only get so far in fighting skill before there just isn't that much left to learn, really. So really, SHOULD WW's greater experience necessarily count for so much anyway?
Of course, it's all moot. Karate Kid is the obvious winner. The only real discussion involves who gets second place. 😉