Muhammad Ali met Leonid Brezhnev in the Soviet leader's Kremlin office yesterday. It was no match. Neither man put a glove on the other. They kissed instead and talked of peace.

Ali came away designated as Brezhnev's personal "unofficial ambassador for peace with the United States," the former would heavyweight champion said, "So don't be surprised if you find me in the White House soon."

At a press conference afterward, Ali said he had come to the Soviet Union last week on a 10-day tour "a little frightened. Things we heard caused us to worry." But he said that his experiences here with the "common folks" he has met and the session with Brezhnev convince him that both Soviet Union and its leader want only peace with the United States.

"It's hard to believe he's a war maker," Ali said of Brezhnev, whom he described as "a quiet, meek gentleman." The 35-minute meeting with Brezhnev, head of the Communist Party, president of the state and supreme leader of its military forces, is without precedent, according to the Kremlin. An official there said Brezhnev, 71, had never before met a foreign athlete for a private session in his Kremlin office.

"All he spoke about was peace," declared Ali. "I'm just a boxer from America and he took time to give me a special five-minute speech about him and his country. All he talked about was peace and love of humanity. He's nothing like the picture painted to me."

Brezhnev gave Ali an autographed copy of his war memoirs, an expensive watch with his signature graven on the back and a Russian gift box for Ali's wife. Then the heavyweight spontaneously hugged Brezhnev, who hugged him back and the two men exchanged kisses on the cheek, a traditional Russian custom for men.

If Ali has won the Soviets - as surely he has, to judge by the crowds that have flocked to him in public places and the intense, positive media treatment - the reverse is also true, to gauge by all that the prizefighter has had to say here publicly.

An accomplished showman and shrewd conversationalist, Ali has adroitly turned aside virtually every question that could possible be described as demanding a critical answer. He and his entourage, which includes his wife and seven other persons, have toured the Central Asian cities of Tashkent and Samarkand and parried reporters' tough questions all along the way, leaving the Soviets purring with satisfaction and Ali pleased with his own performance.

A pilgrim in many respects - from an obscure upbringing in a black section of Louisville, ky., to controversy in the United States and world fame as a boxer and arresting self-promoter, Ali sought out in Central Asia the mosques of his Muslim faith and worshipped there and came away certain that things are good here for all those who wish to practice their religions.

He would not entertain suggestions to the contrary and upbraided an American correspondent here who challenged Ali on his statement that his meeting with Brezhnev was "the most important moment" in his life when he had said a similar thing after a meeting with Moslem leaders in Central Asia.

"I've told my mother I love her more than any woman in the world and I've told my wife the same thing," an angry Ali said. "Would you say I'm being diplomatic in both cases?"

Then turning to the audience, he said, "This is an American reporter looking for trouble. He wants to trap me in front of the whole world to look like a hypocrite when I said it was a great honor to meet Mr. Brezhnev."

Brezhnev's gesture of welcome comes at a time when relations with America are strained and marked by blunt public exchanges of dissatisfaction between the Kremlin and the White House on a whole range of issues. Whether or not Brezhnev's decision to meet with Ali is designed as a signal of a placatory sort is impossible to say.

Ali has always been held in special regard here for his refusal as a conscientious objector to accept military service during the Vietnam war. He is being described in the Soviet press as a fighter for equal rights for blacks in America as well as a great boxing champion, themes which Brezhnev mentioned in his welcoming remarks, saying he knew of Ali's "activities to improve the life of Negroes in the U.S.A."

In general, Soviet officialdom takes a negative view of professional prizefighting as a tawdry sport in which capitalist bettors pay to see contestants commit mayhem against each other. All Soviet boxers are called amateur here, although they are supported by well-financed state-run athletic organizations and the champions among them treated to special privileges.

For Ali, the fact of the meeting with Brezhnev worked like a tonic on his mind, calling up comparisons of his past with his present status in life at a time when his ring career is coming to a close and he is grappling with what to do with the great fame that now attends him.

"No other American movie star or athlete can boast and say I know Brezhnev," he said at his press conference."

"I know Brezhnev . . . for a man that powerful and that great - he don't need me!"

"He had me in his office, looking at me, gave my wife a beautiful case, gave me a watch with his signature on it and I gave him a hug and a kiss on both cheeks and he returned it. That is a great great honor for a Negro from America, a Negro who could't eat with the white folks a few years ago, a Negro who had trouble eating in white restaurants a few years ago. I met (President) Carter and (President) Ford and now I've met the president of the Soviet Union."

These remarks may be paid close attention by Soviet propagandists. The Soviet press is with accounts of the racial inequalities in the United States, in part as a counter to President Carter's personal espousal of greater human freedoms in the Soviet Union.

Ali, remarking that he hadn't seen "one gun or one policeman" during his stay here, had other courtly compliments. He said he and his wife feel especially safe here. When he runs in Moscow streets in an early morning workout, he said, "I don't worry about anybody knocking me in the head and taking my money."

He is scheduled to box three exhibition rounds tonight, going one round apiece with each of three Soviet boxers. Later yesterday, he met George Winooski Tynes, a 72-year-old black man from Roanoke, Va., who came here 36 years ago as a technician, stayed and raise a family and Ali that life has been good for him here.

Ali said Brezhnev "didn't talk about boxing. He seemed to know nothing about boxing, only the name Muhammad Ali. We didn't talk about small things, such as fighting. I don't think he's ever heard the name Spinks."

Of his rematch with Leon Spinks, the former Marine who dethroned Ali in a closely fought match last February, Ali promised, "I want war with Spinks. I will drop bombs on Spinks. I will have sneak attacks on Spinks . . . I'm gonna bury him.'"

Although he has enjoyed himself here, Ali said, he will be happy to return to the United States. "I love America. I love the food in America, the TV, the movies, the highways and cars, the flag and the president.And I also love the truth," he concluded.