US President George W Bush issued one of his strongest rebukes to China on human rights on Wednesday, two days before Beijing hosts an Olympics it hopes will showcase its modern face and economic might.
Euphoric crowds chanted "Go Olympics, Go Beijing" as the Olympic flame was carried through Tiananmen Square on the last leg of its troubled relay before Friday's opening ceremony.
At that ceremony, beamed to an estimated one billion television viewers around the world, a Sudanese-born athlete who fled government-sponsored militia will carry the US flag, in what could be seen as an embarrassment to Sudan and ally China.
Bush says he is attending the ceremony for sport and not for politics, but he plans to pause en route to express "deep concerns" over religious freedom and human rights in China.
"America stands in firm opposition to China's detention of political dissidents, human rights advocates and religious activists," he will say in a speech in Bangkok on Thursday, excerpts of which were released in advance.
A handful of foreign protesters took their chance to grab the spotlight before attention shifts to the sporting contests.
Police rushed to detain two Britons and two Americans who unfurled "Free Tibet" banners from poles near the main "Bird's Nest" stadium, and stopped other public protests during the day.
The mood in Beijing, though, was one of mounting excitement, with most of the 10,500 athletes from 205 countries now in town.
The first competition, women's soccer, began with three matches. The United States, gold medallists four years ago, slumped to a 2-0 defeat by Norway.
Men's soccer, which has drawn Brazil's Ronaldinho, starts on Thursday. Argentina's Lionel Messi could be on his way home after his Spanish club Barcelona won the right not to release him.
At the weekend, the eagerly awaited swimming competition begins in the new "Water Cube" pool, another shimmering landmark for the Olympics. American Michael Phelps is seeking to smash compatriot Mark Spitz's 1972 record of seven golds in one Games.
Phelps tried to puncture some of the hype. "You guys are the ones talking about it ... I'm not," he told reporters.
Flags and Pom-poms
In Tiananmen Square, Beijing's symbolic heart best-known abroad for the crushing of 1989 protests, one of China's most famous sportsmen, 7ft 6in basketball player Yao Ming, said he was overwhelmed as he held the flame above a sea of beaming faces.
"After lighting it, my mind went blank, and then I just wanted to hurry up running ahead," Yao told state media.
Though not fully fit, NBA player Yao will lead China's team when basketball starts at the weekend, also featuring a U.S. squad pumped up to avenge missing gold in Athens four years ago.
Children wore "I Love China" T-shirts and workers waved flags and pom-poms, while drums and cymbals resounded around Tiananmen under a portrait of late revolutionary leader Mao Zedong.
China's Communist leaders hope such images of the torch's final passage through the host city will help banish memories of Tibet protests that dogged the flame elsewhere in the world.
Police were quick to react to Wednesday's Tibet protest, taking 12 minutes to remove the four, before asking them to leave the country, according to state media.
The Dalai Lama, exiled spiritual leader of the Tibetan people, who has repeatedly distanced himself from protests against the Games, sent his best wishes to China.
"This is a moment of great pride to the 1.3 billion Chinese people," he said from his home in northern India. "I send my prayers and good wishes for the success of this event."
US athletes chose a former Sudanese refugee, one of the so-called "Lost Boys", to carry their flag at the opening.
Lopez Lomong, now a middle-distance runner, fled on foot from rampaging government-sponsored Arab militia at the age of six in 1991, becoming separated from his parents at the height of a civil war in southern Sudan.
After years in refugee camps, Lomong and thousands of similar children were resettled in the United States.
The US government also said it would protest to China over its decision to revoke the visa of Olympic gold medallist Joey Cheek, an activist for the western Sudanese region of Darfur.
US swimmer Amanda Beard became the first athlete at the Games to cross the divide from sports into politics when she took to the street to unveil a nude photo of herself saying "Don't wear fur". Police had banned her from holding a news conference.
And in a clutch of such political statements, three Americans shouted slogans decrying forced abortions and religious repression in China before police intervened, while a Tibet film got a secretive premiere to reporters in a dingy hotel room.
Demonstrations around the torch's international legs offended many Chinese, who see the Games as a moment of national pride for a nation some view as the emerging 21st century superpower.
"It's not just about the sport, it's about the image of China," said Xi Li, among the officially organised torch crowd.
"Chairman Mao would have been happy if he were here today!"
Sadly for organisers, the start of the flame's passage through Beijing took place under smog-filled skies.
Some $18 billion of clean-up measures have reduced contamination to safe levels, according to Games chiefs, but not produced the sunshine and blue skies China longs for.
Anxious US cyclists arrived with face-masks on, though that drew disapproval from the International Olympic Committee which said it was unnecessary. The athletes later apologised.