That all depends on who the competition is. Defeating Slade (yes I know, that's not him in the art we saw) or any of his children? Okay, sure. Slade might be pushing it but it'd be far from the first time he was defeated by a teenager.
But if characters like Shiva, Bronze Tiger, and Cheshire are involved I might have to call some BS on him winning.
Damian is an amazing fighter. But I don't think he's that amazing. Even when we disregard his loss to Thomas Wayne that had no logical reason for happening.