MUHAMMAD ALI took some good shots on his diplomatic tour of Africa -- mostly lefts, mostly to the heart. They came from sports figures, journalists and governments arguing that the former world champion, rather than trying to talk them into boycotting the Moscow Olympics to protest the Soviet invasion of Afghanistan, should be wising up to black Africa's far greater aversion to South Africa. He ended up by saying, in Nigeria -- a country still grateful for the arms Moscow sold it in its civil war in the 1960s -- that "the No. 1 fight with me is not Russia. The No. 1 fight with me is South Africa."

But if Mr. Ali sounds so dazed by his exposure to black Africa that he couldn't find his way back to his own corner, that just isn't so. For while he took some punches, he gave back more and won his diplomatic bout on points.He seems to have understood perfectly that, to get a hearing for his message, he had to show himself ready to receive the Africans' message. The credibility that he brought with him by virtue of his Vietnam War experience and his Moslem faith, and which he enhanced by his openness to African concern over South Africa, was put to good use in his appeals on Afghanistan. How else do you explain the intrusive Soviet effort to talk him out of going in the first place, and the chilliness with which the governments of Nigeria and Tanzania, which are sending athletes to Moscow, reacted to his highly publicized approaches to their publics?

Some American blacks found it patronizing of President Carter to send a black boxer on this mission to Africa. The multi-racial, multi-ethnic makeup of America condemns us, it seems, to an unending series of concentric debates over the proprieties of foreign assignments like this one. We would simply note that if you are looking for someone to communicate with the African public on a sports-related issue with a Moslem aspect, then Clark Clifford and Zbigniew Brzezinski, to name two others who have recently been on the Afghan diplomatic circuit, do not come instantly to mind. In any event, blacks and others put off by the dispatch of Muhammad Ali to Africa might wish to give more attention to the message he is bringing back. It is that if the United States wishes to enlist one large sector of humanity, in Africa, in its newly intensified campaign to contain the Soviet Union, then Americans are going to have to pay more heed to black Africa's feelings about South Africa. The Ali mission made that point with all the force of one of the ex-champion's right hooks.