Two rounds? Why, certainly.
BR 12 and 19 - two hits. BR 2 and 5, for 11 points of damage.
Then BR 10 and 10, for two more hits. BR 1 and 3, for 8 points damage.
Yup - that's 19 points in two rounds. I'll take questions from the audience now?
"Yes - Ms. Threnody - I appreciate your magic, but I was wondering exactly what 'it' is, and how one goes about doing 'it'?"
Well, allow me to refer you to the lines above. For I believe that stands as a model for the 'it' of which you speak, and how that 'it' might be accomplished. Furthermore, while it is not (as such) entirely necessary, one might include as an addendum the utterance: 'bitch!'.