Author Katherine Dunn spent more than 10 years training with the fighters of Knott Street Boxing Club in Northeast Portland's Matt Dishman Community Center. But Dunn, best known for her novel "Geek Love," had never fought for a purse until Tuesday afternoon. Dunn, 64, was carrying a bag of groceries from Trader Joe's to the Northwest Portland home where she has lived for more than 30 years when someone yanked the purse strap on her left shoulder so hard it spun her around.