A pair of potentially explosive match-ups will be shown during SHOWTIME’s Free Preview Weekend when WBC Lightweight Champion Jose Luis Castillo (51-6-1, 45 KOs) takes on former IBF 135-pound titleholder Julio “The Kidd’’ Diaz (30-2, 22 KOs) and undefeated Jeff Lacy (18-0, 14 KOs) risks his IBF super middleweight crown against Rubin “Mr. Hollywood’’ Williams (26-1, 15 KOs) on SHOWTIME CHAMPIONSHIP BOXING Saturday, March 5. The world championship doubleheader, which will be co-promoted by Top-Rank, Inc., and Gary Shaw Productions, LLC, will take place at Mandalay Bay Resort & Casino in Las Vegas and start at 10:30 p.m. ET/PT (delayed on the West Coast). [details]