Sugar Ray Leonard moved a step closer to the world welterweight championship today by stopping Armando Muniz of Los Angeles after six one-sided rounds at the Springfield Civic Center.

Muniz, who failed in four title fights -- two each against Jose Napoles and Carlos Palomino -- called it quits seconds after the bell had rung to end round six. It went down in the books as a seventh-round TKO.

Muniz, 32, said an injury to his left arm was the reason he failed to finish for only the third time in 63 professional fights.

But Leonard was in control from the opening bell and dazzled the slower Muniz with combinations. Leonard circled to his left and jumped in with hard lefts and rights to the head of Muniz.

Leonard did the "All shuffle" midway through the first round, bringing the crowd of more than 6,000 to its feet. Muniz's only answer to Leonard's assault that first round was a glancing left hook to the head.

Leonard dominated the final round against his plodding but willing opponent. A straight right at the bell caught Muniz squarely on the jaw and staggered him.

The victory, Leonard's 17th without a loss as a pro, kept alive a bout at Capital Centre on Jan. 11 against Johnny Gant of Washington, D.C. Leonard weighed 149, two pounds fewer than Muniz.

Both judges and the referee, Dick Flaherty, gave all six rounds to Leonard.

Leonard's brother, Roger, 158, used a long left jab and a hard right hook to win a six-round unanimous decision over Sean Mannion, 154, of Boston. It was Roger Leonard's third victory since turning pro.

Cousin Odell Leonard, 160, fought to a six-round fraw with Johnny Harris, 163, of East Hartford, Conn.