Renekton might be able to, but neither one of you necessarily wants to fight the other once you get tanky enough. They both have a stun and only Renekton's W and auto attacks are blocked by Jax's E. Then Renekton can heal with his Q and do constant DoT with his ult.
Pre-6, Renekton should be able to out harass and outlast Jax due to being manaless and having sustain.
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