The welterweight championship match between Sugar Ray Leonard and Roberto Duran already has sold out at Madison Square Garden, the Felt Forum and Aqueduct Race Track in New York, all of which will show closed circuit versions of what promises to be a ring war.

The publicity blurbs citing this fight as "the Battle of the Decade" do not overstate the case. Only Montreal, the host city to the fight, is having trouble selling tickets. The $500 and $20 seats are gone but others in the scale are not moving fast enough to ensure the promoters a profit. The Montreal Olympic Stadium seats 77,269.

Gamblers appear to be holding out their heavy belts until the last minute, inflating the odds of 2 to 1 favoring Leonard. The odds should come down by fight time.

The fight itself appears to be a tossup.

Leonard has the faster hands, Duran the experience. Leonard, at 24, is five years younger than Duran, who has appeared sluggish in his last few fights, but knowledgeable fight people know that the Panamanian has not been challenged for his best effort since he won the lightweight title from Ken Buchanan, a brilliant boxer, in 1972. Duran will be ready for what might be the most ferocious battle since Rocky Graziano and Tony Zale destroyed each other more than 30 years ago.

In early rounds, the question appears to be whether Sugar Ray can establish and hold his part of the no-man's land that separates two fighters from one another.

Duran will try to penetrate, while Sugar Ray will use movement and counterpunching as his main defense.

Duran is a slow starter, while Sugar Ray, with his catlike movements, appears ready from the opening gong.

Both are good punchers and each has the instinct for finishing even a slightly dazed opponent. Leonard is reminiscent of former champion Johnny Saxton in many ways, although Leonard has the heavier punch and a more positive attitude.

Duran resembles a miniature Rocky Marciano: visibly aggressive while still staying out of the range of many punches.

Leonard will move and Duran will press. They will trade punches early in the first round and neither will be able to stick to a prefight strategy. The action will be fast and furious, with each being stung in turn. Sugar Ray, who does not take a good punch, will have his work cut out for him early. r

Within three rounds the fight will have established whether Sugar Ray can hold off the strong pressure Duran will put on.

We see Sugar Ray within the time ripping a sharp right to the body and following with the left hook to the chin of Duran that will put Duran down and out for the night.

Every great athlete, at one point or another, climbs the mountain and commands all he surveys. Friday night Leonard will stand at the mountain top.