[youtube http://www.youtube.com/watch?v=x1jOfdtUQqw?rel=0&w=640&h=480] shosports Published on Dec 15, 2013 Highlights from the explosive December 14th Showtime Championship Boxing event including Beibut Shumenov, Tomas Kovacs, Keith Thurman, Jesus Soto Karass, Leo Santa Cruz, Cesar Seda, Adrien Broner, and Marcos Maidana. Related articles Marcos Maidana unanimously outpoints Adrien…