Not sure all of the locales this term is used in. However, when I was growing up in the hood of St. Louis. Booyahka was common terminology when referencing someone getting punched very hard and unexpectedly.
If someone got waylayed in a fight, it wasn't unheard of for someone watching to yell "Booyahka!" or "Bookup!"
by Booyahka October 10, 2009
by xitzmarcusx February 18, 2003