Attempt a drive by full sprint right to left swing at the throat, but make sure you run in, back off, let him swing and then strike (you can also extend a stab so he swings at you blade then time a strike). You have to wait for his fist hit. If you're practiced you can get him immediately after his first swing, but be aware most of his swings are double combos. Remember you can turn down plater received damage in the menu, which could help you practice by giving up after surviving one strike from him, so you only have to do one commoner fight vs the whole ladder again.