In April, 1971, at the height of the Cold War, a bitterly anti-American communist China invited a lowly American table tennis team to visit Beijing.

The world was stunned and mystified: Why had implacably hostile China lifted its ban, in effect since the founding of the people's Republic in 1949, on visits by Americans?

Chinese Premier Zhou Enlai supplied the answer a few days after the Americans and other foreign table tennis teams arrived in the Chinese capital. Welcoming them over hot cups of tea, Zhou declared the era of U.S.-China enmity over.

The American team's visit _ and that of three American reporters allowed to accompany it _ opened the first crack in Mao Zedong's wall of hostility, setting the stage for President Richard Nixon's historic visit 10 months later and eventually for the ``open door'' policies that would spur China's economic miracle.

Dubbed ``pingpong diplomacy'' by an astonished world, the trip 35 years ago this weekend is a useful reminder of the role sports has played in helping foreigners to put a human face on China. As Beijing prepares to host the 2008 Olympics, it hopes the games will create a positive image in the minds of a world sometimes wary of China's rising power.

In early 1971, Mao's China was largely closed to the world and had no diplomatic ties with the United States. It routinely rejected offers of American help after natural disasters. Nor did the U.S. always extend a hand. In 1956, Secretary of State John Foster Dulles threatened to jail any American reporter who accepted an offer to visit China.

The surprise invitation to the U.S. table tennis team came from the victorious Chinese players at the end of the world championships in Nagoya, Japan. Reporters John Rich and Jack Reynolds of NBC and I received visas

The accepted wisdom at the time was that the visit was engineered by the urbane, international-minded Zhou, who wanted to establish diplomatic ties with Washington as a hedge against Soviet expansionist plans.

Fearing a public rebuff from the notoriously anti-communist Nixon, the theory went, Zhou decided to test American public opinion. What better way than to display good will toward the 17th-ranked American players? If American reaction proved negative, China would not lose face.

But ``Mao: The Unknown Story,'' a recent biography by Jung Chang and Jon Halliday, says it was Mao, not Zhou, who decided on an impulse to invite the Americans.

True or not, the fact remains that by the time of pingpong diplomacy, Mao was more powerful than most Chinese emperors dating back 2,500 years. His pictures and published works were the objects of veneration in what was then the midpoint of the blood-drenched Cultural Revolution, the radical movement he, his wife and their cohorts launched in 1966.

But the China we Americans saw in Beijing was one of smiling crowds waving the ``little red book'' of Mao's quotations.

From their arrival April 8 through their 10 days in China, the American pingpong players proved superb diplomats just by being themselves. Wherever they went _ the Great Wall, the former imperial Summer Palace _ they touched off spontaneous cheers and applause. ``Meiguo ren hen hao'' _ Americans are great _ the crowds shouted.

The cheers mounted as they played exhibition matches before 18,000 spectators, revealing a reservoir of good will among Chinese which no amount of anti-American propaganda had been able to suppress.

The widespread jubilation which greeted the Americans helped persuade Nixon to make his historic journey to Beijing in early 1972, radically altering the Cold War equation. It suited Nixon's plans for eventual military withdrawal from Vietnam and became among the most acclaimed decisions of his flawed presidency.

It enabled the United States to join countries such as Canada, Britain and France that already had diplomatic relations with China, although it would be eight more years before Washington and Beijing exchanged ambassadors.

By then Mao was dead and his pragmatic successors would embark on the reforms which are making possible the Beijing Olympics of 2008, a world event unthinkable in the tempestuous, closed China of 1971.