On paper you would think J'Onn would win. But it doesn't necessarily turn-out that way in practice. If J'Onn could do it by himself, when the JLA had the intention of killing Superman(during the KING OF THE WORLD storyline), J'Onn wouldn't have needed a bunch of help to restrain Superman while Kyle worked on making Kryptonite. Oh yeah, after Orion was the one who was the most effective. Or the time him, Power Girl and a bunch of others tried to restrain him and failed.
We also have J'Onn stating Kryptonians can basically shut their minds off from telepathy.
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And while Superman had the element of surprise here, and he had the JLA's tech helping, this sure seems to show the speed difference between the two.
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And J'Onn might be more versatile, but I don't see it making a difference with Superman's superior speed, strength, durability, energy projection, plus telepathic resistance. Not to mention he's simply shown to be a better, more effective fighter, both in hand-to-hand combat skill and ability to use his powers.
I'm going to be laughing my ass off after getting over shock if it just so happens that this topic hasn't been done before.