Tonight (Friday) on Showtime it's James De la Rosa vs. Tim Coleman (light middleweight) and Fernando Guerrero vs. Tyrone Watson (middleweight) from Salisbury, Maryland. Also, TeleFutura has Mike Alvarado vs. Manuel Garnica (welterweight) and Brandon Rios vs. Manuel Perez (super featherweight) from Denver, Colorado.

Tomorrow (Saturday) night from Temecula, California, HBO has the interim WBC light middleweight title fight between Sergio Martinez and Alex Bunema, plus Alfredo Angulo vs. Andrey Tsurkan (light middleweight) and Yuriorkis Gamboa vs. Marcos Ramirez (super featherweight).

Also in action this weekend, but not televised in the U.S., are Delvin Rodriguez, Eddie Chambers, Arthur Abraham vs. Raul Marquez, Kassim Ouma, and Juan Manuel Lopez vs. Cesar Figueroa. Check our complete fight schedule for details.

The boxing reality series "The Contender" is coming back for a fourth season ... but a lot of changes are in store. The series will have a new home - the Versus network - as well as a new host, two new trainers, a new weight class and a fresh field of 16 fighters vying for the top prize. Find out everything you want to know about The Contender: Season Four.

Entering the 12th round, Sugar Shane Mosley (45-5) was ahead of Ricardo Mayorga (28-7-1) on two of the three judges' scorecards (107-102, 105-104, 104-105). If Mayorga won the final round, the fight would have been scored a controversial draw (Mosley should have been further ahead on the cards). Mosley, however, was not prepared to let the judges decide the outcome. Mosley went after Mayorga aggressively and sent him to the deck late in the round. Mayorga got to his feet but Mosley decked him again with a perfect left hook and referee David Mendoza stopped the fight without bothering to count. Time of the stoppage was 2:59 -- just one second remaining in the bout. For the fight, Mosley was guaranteed $1.5 million and Mayorga was guaranteed $550,000. Mosley, 37, may be a bit past his prime but would still provide a great test for any of the current welterweight champions: Antonio Margarito, Paul Williams, Andre Berto or Joshua Clottey.

On the undercard, WBC welterweight champ Andre Berto (23-0) successfully defended his title with a unanimous decision over former champ and Contender finalist Steve Forbes (33-7). The scorecards all favored Berto by a wide margin: 118-109, 118-109 and 116-111. Berto earned $300,000 while Forbes received $150,000.

"Sugar" Shane Mosley (44-5) takes on Ricardo Mayorga (29-6-1) tonight at the Home Depot Center in Carson, California. Mosley, who has never ducked anyone, hopes a win at junior middleweight over Mayorga will lead to a title shot at welterweight against Antonio Margarito. On the undercard, undefeated WBC welterweight champ Andre Berto (22-0) defends his title for the first time against Steve Forbes (33-6). Forbes, a former "Contender" finalist, lost a unanimous decision to Oscar De La Hoya in May in his most recent bout.

HBO coverage begins at 10:30 PM ET/7:30 PM PT.

Complete Schedule of Upcoming Fights