This Saturday, SHOWTIME CHAMPIONSHIP BOXING returns to Southern California with an action-packed tripleheader featuring Interim WBA Welterweight World Champion Keith Thurman vs. Julio Diaz in the main event.  In the co-features, Lucas Matthysse faces John Molina Jr., and Omar Figueroa Jr.defends his WBC Lightweight World Championship against Jerry Belmontes.  The telecast begins at 9 p.m. ET/6 p.m. PT, immediately following ALL ACCESS: Mayweather vs. Maidana Episode 2.