For all the marbles

Thursday, May 5, 2005 | 9:41 a.m.

Jose Luis Castillo has emerged as the hardest-working man in the boxing business.

A two-time and reigning WBC lightweight champion, Castillo successfully defended his title against Joel Casamayor last December, then did it again against Julio Diaz in March.

Yet Castillo insists his busy schedule will not be a liability Saturday night when he takes on Diego "Chico" Corrales in a lightweight title unification bout at the Mandalay Bay Events Center.

"Fortunately, I wasn't hit a lot in any of the other fights, and I have been winning them," Castillo said. "I don't think I'll be hit Saturday night either."

Castillo (52-6-1, 46 knockouts) will risk his WBC belt against Corrales (39-2, 32 KOs), who puts his WBO title on the line. Showtime (9 p.m., tape-delayed in the West) will televise the bout.

In another featured match, Juan Manuel Marquez (43-2-1, 33 KOs) and Victor Polo (34-4-3, 24 KOs) square off for the world featherweight championship.

Promoter Bob Arum, whose Top Rank will present the card along with Gary Shaw Productions and Banner Promotions, is counting on Castillo, an aggressive power puncher, to put on another exciting show.

"Both of these guys come to fight," Arum said. "Jose Luis is probably the most active top fighter in the sport. Nowadays, three major fights in six months is a tremendous number."

Joe Goossen, Corrales' trainer, believes that flurry of relentless activity could lead to fatigue -- or even burnout -- for Castillo, giving an advantage to his well-rested fighter.

"Three camps, even two camps, in a row can be very tough on a fighter," Goossen said, "especially when he's fighting champions each time."

Castillo, who prepared for the fight by training in the mountains by Mexico City, did not waver in his conviction that he'll win Saturday, but he did acknowledge that three consecutive camps can amount to a grueling exercise.

"Not so much physically, but mentally," Castillo said Wednesday at a training session at Mandalay Bay. "Just spending all that time in training camp, it can be difficult. After this fight, we're going to have a rest."

Corrales, of Las Vegas by way of Sacramento, has not fought since stopping Acelino Freitas in the 10th round last August for the WBO title.

"I feel great because I've been rested; he says he feels great because he's been so active," Corrales said. "You could take it either way. ...

"All I know is at some point we're going to end up head-to-head ... at one spot in the middle of the ring, throwing bombs."

Given the crowd-pleasing styles of both boxers, Saturday's match could develop into a candidate for the best fight of the year -- perhaps joining the front-runner, Erik Morales vs. Manny Pacquiao in March; a dark horse, Oscar Larios vs. Wayne McCullough in February; and another potential scorcher, Felix Trinidad vs. Winky Wright on May 14.

"I leave that (fight of the year discussion) for the media and the fans," Corrales said. "But I personally look at it as it could be a really painful fight (for either boxer). ...

"Could this become one of those legendary nights? Yeah, I think it has that potential. And that's something that excites me. It thrills me to death."

The magnitude of the matchup adds to the fight's allure, said Shaw, who promotes Corrales.

"This is not one of those fights where you say, OK, if he beats him, then there's another one out there," Shaw said. "This is it. Two top-ranked fighters, the best lightweights in the world."

Castillo brings a solid chin and likes to charge toward his opponent in the manner of his fellow Mexican ring warriors.

Corrales hit the canvas in each of his two fights against Joel Casamayor -- they went 1-1 in 2003 and 2004 -- but he brushed aside concerns about his chin Wednesday.

"The real question is how does (Castillo) react when my power hits his chin," Corrales, 27, said.

"... (Castillo) is a consistent, true champion. He never ducks anyone. I believe it can be a firefight, tooth-and-nail."

Corrales figures to rely on his long-range jab and his ability to sting opponents with punches thrown from tricky angles -- though he's willing to brawl as well.

Both fighters appeared well-conditioned Wednesday, and Castillo, 31, said he's in top physical shape -- though he does not expect a long, drawn-out affair Saturday.

"It's gonna be a brawl," Castillo, of Mexicali, said. "I think it's gonna be a quick night. We're going home early. ...

"One of us is going down, and if he goes down he's not coming back up."

Corrales is a minus-150 favorite, according to odds in the Mandalay Bay sports book (gamblers risk $1.50 for each $1 they're trying to win). The underdog in the fight, well aware of the betting line, took issue with it Wednesday.

"It's not the first time the experts are wrong in one of my fights," Castillo said. "I'll prove them wrong again. This guy should not be favored over me."