Well, that's not enough to take Maugris down all on its own, but he certainly feels it. However, that blood gets his attention, enough for him to make another lunge at Otoha. This time it's obviously an attempt to get hold of the man rather than just a wild strike, though it's still a rather inexpert attack. His lack of experience brawling means he's relying on brute strength, and while he has a lot of that, it doesn't do much good if he can't connect.

And considering Otoha knows Maugris's nature, he can probably guess what the vampire will attempt to do if he manages to get him pinned.