By Denis Hamill (New York Daily News)

There's gonna be a brawl.

Fists will fly and blood is gonna flow all over town.

That's what its come down to. Sometimes it takes tough guys who bleed for sport to emphasize just how critical the blood shortage is in this city.

And so, on April 14 at 7 p.m., the NYPD-FDNY joint boxing teams will duke it out against the joint Los Angeles Fire and Police Boxing team at the armory on E. 26th St. and Lexington Ave. in an event called "A Fighting Chance: We're Out for Blood." Tickets are $20.

"New York City is in a critical need for blood at this time," says Pat Russo, a retired 72nd Precinct cop who runs the NYPD boxing team called the Fighting Finest and the citywide PAL boxing program, keeping tough street kids in boxing rings instead of The Bing at Rikers. "The purpose of this event is to draw blood and awareness for the New York Blood Bank."

Russo and Fighting Finest partner Lt. Dave Siev of the firearms unit will also run a series of blood drives leading up to this event: Today, 1st Precinct, 16 Ericsson Place downtown, 12:30 p.m. to 6:30 p.m.; tomorrow, Queens North Task Force, 137-58 Northern Blvd., Queens, noon to 7:30 p.m.; Thursday, 77th Precinct, Utica Ave. and Bergen St., Brooklyn, 12:30 p.m. to 6 p.m.; Saturday, Michael Buszak Little League, 193rd St. and Amsterdam Ave., 11 a.m. to 6 p.m., and Monday, 1 Police Plaza, 9 a.m. to 6p.m.

"During these drives, we will especially urge minorities to join the blood-marrow pool because the pool for minorities in general is at especially low and dangerous levels," Russo says.

"Minorities who give one extra vial of blood will enter the special bone-marrow pool," says Siev. "We're working to get the same kind of program for Caucasians. But it's a more severe problem for minorities because if you ever face a life-threatening blood disease in the leukemia family, the chance of finding a bone-marrow match outside of family circles is very low. For Caucasians it's like a 60% to 80% chance. It's less than half that for minorities. So we're urging minorities to please give desperately needed blood."

These fights aren't for world titles, but they're always highly entertaining. "We have a guy named John McCann, a retired NYPD detective, who fought in the Golden Gloves back in the late '80s coming out of retirement at 42," says Siev. "He's fighting a re-rematch of a 15-year-old decision he won over a retired LAPD SWAT team cop named George Lopez, who represented Argentina in the Olympics. McCann runs a limousine service now in New York, and Lopez owns two restaurants in L.A. These fortysomething guys are squaring off for charity and to settle an old score."

The NYPD-FDNY boxing team might be the forum where this silly Battle of the Badges between the Finest and the Bravest that's been hyped by the press is in least evidence. "None of that sibling rivalry ever comes up," says Siev. "Ever since 9/11, we've traveled all over the country and the world as a joint team. ...Everyone cheers us as a New York team."

"There's never any animosity between the fighters," says Russo. "My experience, and people outside boxing circles never believe this, is that the vast majority of guys who get in the ring are nonviolent outside the ring. They have nothing left to prove. The street kids from PAL come into the ring and learn discipline and self-confidence and respect."

Russo says soon after getting out of the Police Academy he climbed into the ring to earn the confidence he thought he'd need on the job. "Boxing gave me self-assurance to handle hairy situations like domestic disputes," he says. "If I felt comfortable in my own ability to handle a situation, I knew I wouldn't be reaching for my gun in panic. Boxing helps you assess a situation in a cool, strategic way - the way you size up an opponent in a ring. And that's why nothing in this city helps break down the barrier between street kids and cops like PAL boxing. You simply can't measure in numbers how many violent crimes PAL boxing prevents."

But we can measure the success of the program inside the ring. Nine PAL boxers are fighting Thursday and Friday in the finals of the Daily News Golden Gloves tournament.

We can also measure how much blood and money the NYPD-FDNY boxing team can raise at its very important event this week and next.

"We urge everyone to come to the fights," says Russo. "Cops and firemen who give blood get a half-price coupon for the fights. Civilians will receive small police novelty items while supplies last."

These fights are literally for life.

For more info, call Lt.Dave Siev at (917) 882-4275, or go online (www.finestboxing.com).