In a terrific fight in the second-half of an excellent world championship doubleheader, IBF/WBO/WBA lightweight champion Nate Campbell, 32-5-1 (25), of Jacksonville, Fla., will make his first defense against undefeated two-division world champion Joan Guzman, 28-0 (17), of Brooklyn, N.Y., on Saturday, Sept. 13, 2008, live on Showtime Championship Boxing at 9 p.m. ET/PT, delayed…