It's only by comboing the * out of her, getting her chaosed and then getting the Water Main under lock so that they aren't able to heal her right afterwards. Or you kill her with brute force and combos. I'm able to do it if I'm up against a really weak person, but they're likely to stack Poison + Neuro and St. Heal, and of course there's initiative.

Weirdly enough, I've come across this team several times where the person running it didn't spam me with TenTen's mystery the first round despite having the chakra to do so...