NO MATTER WHAT Sugar Ray Leonard says, the doubts and speculation will continue -- after all, wasn't he ambivalent up to the last minute? But believe him, and you have a new champion -- of good sense, good health and dignity, in a sport with pitifully little of any one of these qualities. Can it really be that one of the most impressive boxers of all will quit with his body, brains, talents and finances in tip-top shape, with a bright future ahead?

Maybe, just maybe, we and our children will not be treated to a sequel of the Last Joe Louis or the Last Muhammad Ali, paunchy, slow and uncharacteristically out of place in the ring. Mr. Leonard, with dazzling agility and consistency, gave boxing a lift it sorely needed; there was athletic proof that training, ability and grace can make an otherwise crude sport into a match of skills worth witnessing.

But the toughest battle surely has to be against temptation -- to resist that one "last" shot for the big dollars that will never be matched another way. If Mr. Leonard has truly won this fight, the challenge of finding continued self-satisfaction lies ahead. For other boxers, this retirement struggle could take a full 15 rounds and still end up as a split-decision humiliation. But Mr. Leonard has been an exceptional winner up until now -- and he has what it takes to stay that way.