Tickets for “Melendez vs. Thomson,” priced from $30, are on sale at the HP Pavilion box office (408-287-7070) as well as at all Ticketmaster locations (408-998-TIXS), Ticketmaster online (www.ticketmaster.com), and on Strikeforce’s official website (www.Strikeforceusa.net).

Strikeforce World Lightweight (155 lb. limit) Champion, Gilbert “El Nino” Melendez (14-1), will defend his crown against number one contender and Bay Area arch-rival, Josh “The Punk” Thomson (14-2), in the main event of Friday’s Strikeforce affair.

In another championship showdown, Bobby Southworth (8-5) will put his Strikeforce World Light Heavyweight (205 lb. limit) title on the line in a rematch with Anthony “El Toro” Ruiz (20-10). Ruiz was declared the winner of their initial meeting on November 16, 2007 after a cut Southworth had sustained during the fight prompted the ringside physician to order a stoppage at the :52 mark of the second round.

Joe “Diesel” Riggs (27-10) will battle rising star Luke Stewart (5-1) in a 178 lb. limit catch weight fight. Stewart was originally slated to face “Mr. International” Shonie Carter. A hand injury, however, forced Carter to withdraw from the contest last week.

Lightweight (155 lb. limit) Brazilian Jiu-Jitsu stud Nam Phan (14-4) will attempt to hand knockout artist Billy Evangelista (6-0) the first loss of his career.

Making the fifth start of her professional mixed martial arts career, Cung Le female protégé, Elaina “Beef” Maxwell (2-2), will take on Miesha Tate (1-1).

HP Pavilion doors will open at 6 PM for “Melendez vs. Thomson” and the first preliminary bout will begin at 6:30 PM. The live HDNet telecast of the event will start at 7:30 PM PST/10:30 PM EST and the main card will commence at 8 PM.