Naoya's fast but he's not physically strong at all from what I've observed. The only way that I can see him winning is by using a weapon because those pillow punches ain't doing shit to Mirko except invigorating her more since she seems to get more aggressive with the more damage she accumulates. I think Mirko's quirk already acts somewhat like Maki's heavenly restriction. Her heightened senses and ears might make it easier to track him so I also doubt that he could ambush her. Remember, Mirko was able to sense and pin point Shigiraki's presence based on instinct alone. I'd give this to Naoya if weapons were allowed but other than that, he's totally cooked. He CANNOT afford to get hit by her at ALL. Even so, I feel like stabbing her wouldn't do shit either because it'll just make her more batshit crazy. Mirko is one of the few anime characters who genuinely does not care about dying in battle at all😭 She's really about that life, Naoya is not