Today at the Water Cube, Phelps picked up two more gold medals, making it five straight golds -- and each win set a new world record. Phelps won in the 200-meter butterfly, swimming blind after his goggles filled with water. And Phelps was part of relay team that later struck gold again, in the 4x200-meter freestyle.
Following his six gold medals at the 2004 Athens Olympics, Phelps now sits alone as the only athlete to win 11 gold medals.
"Growing up I always wanted to be an Olympian. Now to be the most decorated Olympian of all time, it just sounds weird saying," Phelps told the AP.
Phelps admitted capturing the medals record was a distraction. "I was just trying to focus on my next race, but I just kept thinking, 'Wow, greatest Olympian of all time.' It's a pretty cool title."
His competitors, left in his wake, are in awe. "He is just a normal person, but maybe from a different planet," said Russia's Alexander Sukhorukov, who managed to win a silver against the Phelps-led American juggernaut.
And the Chinese are also duly impressed.
Although he's not contributing to China's closely watched medal count, Phelps has accumulated millions of Chinese fans as he collects gold medals in a country whose utmost priority is bringing home as much gold as humanly possible. Phelps swims like a fish, some Chinese fans say with admiration.
"Phelps is the merman legend of the whole world," a blogger wrote, referring to the male version of the mythical mermaid.
"World records tremble when they see Phelps," a Sina.com blogger declared this morning.
"It is a tragedy to be born in the same time with a sport genius, how many superstars have been eclipsed by the Phelps' legend?" lamented another impressed Sina.com blogger.
Riding a wave of economic development and scientific advances, the Chinese are asking openly if they, too, could produce a Phelps. Readers of the People's Daily, China's most widely circulated state newspaper, wondered if Phelps could have succeeded as a Chinese athlete.
"If Phelps was born in China, he might not be as successful as he is now," a reader wrote in response to the news that Phelps picked up two more gold medals. Journalists and readers asked how much of his dominance Phelps owes to the American system of training, dramatically different from China's, which is modeled on the old Soviet system.
Readers who posted comments wondered how much state-of-the-art American facilities and the family-oriented, friendly training environment at home mattered in his success.
Others are analyzing Phelps's physical prowess.
"Judging from his body type, he is almost a perfect swimmer," said Shanghai Sports Science Research Center research Principal Li Zhijun. Li cited Phelps's armspan, which exceeds his height.
Whatever Phelps is, he is a champion of epic proportions. Now that he is the winningest Olympian ever, two questions remain: how far he will he extend his gold-medal lead, and will he beat the record of seven for the most gold medals in a single Olympic Games -- set by Mark Spitz at the 1972 Munich games. Spitz also set a world record in each of his gold medal races. Phelps has thus far done the same, going five for five in Beijing.
Whether Phelps tops Spitz, the confident consensus is that he's not through yet: with three more races to go in Beijing, his 11 career gold medals probably won't stand for long.
"There is still something left in the tank," Phelps told AP. "I've got three races left, so there had better be something left in the tank."
Chinese Women Gymnasts Win, but Are They Legal?
As Michael Phelps swam towards more gold, the Chinese women's gymnastics team avoided major mistakes to claim a gold medal for China in the team finals, just as the Chinese men did. The United States and Romanian women took silver and bronze respectively.
Inside the National Indoor Stadium this morning, the pressure on the Chinese team was palpable. When star Cheng Fei fell off the balance beam, she rushed off the platform, devastated. Every person inside the sold-out venue seemed to gasp in disbelief.
But the Chinese team rallied to win the gold, out-flipping and out-balancing the United States team by merely one point.
Five-time Olympic champion gymnast Nadia Comaneci told ABC News that the pressure on the Chinese team this Olympic season has been enormous.
"They carried the entire wall of China on their back because they feel so much that they had to deliver," she said. And deliver they did.
The Chinese team finals ended with convincing results, but many remain unconvinced that the Chinese athletes are yet 16, the cut-off age for competing in the Games.
In July, sports registration lists on Chinese gymnastic Web sites obtained by ABC News suggested that half the stars of the Chinese women's team - Yang Yilin, Jiang Yuyuan, and He Kexin - did not meet the minimum age requirement of turning at least 16 in 2008.
When concerns and questions were raised, Chinese team officials provided copies of their passports and national identification cards to the international gymnastic federation (FIG) and ABC News. The documents indicated they were eligible for competition. But many have questioned whether the documents were created for the sake of Olympic gold.
Comaneci, who has been closely following the women's gymnastics competition in Beijing, told ABC News, "It's always been controversial about He [Kexin]'s age. But their passport says one thing so there's nothing anybody can say about it," she shrugged.
Like Comaneci, gymnastics fans and Chinese news media have shrugged off the age controversy. Unlike the pairs figure-skating judging scandal at the 2002 Salt Lake City winter games, the gymnasts' questionable ages haven't attracted much attention.
It's tough to tell the ages of gymnasts in general, since they are typically more compact athletes. Some Chinese might look younger and smaller than Westerners of the same age. There is no medical way of measuring exact age.
But there are some startling physical differences. On the medal podium, the Chinese team was dwarfed by the Americans and Romanians, who were strikingly taller and more muscular than the gold medalists. On average, the Chinese gymnasts are 3 and a half inches shorter and 30 pounds lighter than their American counterparts. The smallest American is the 16-year-old Shawn Johnson, who is listed at 4' 9", 90 pounds. She is the only American team member under 5 feet.
At the age of 14 and a half, Comaneci was a kid herself when she won gold at the 1976 Summer Olympics in Montreal, scoring the first-ever perfect 10.0 score in Olympic history. At that time, gymnasts were required to turn fifteen during the calendar year of the Games.
Comaneci disagrees with the new age requirement, set by the FIG. "I don't think that helps. Because if the kid is great at fourteen, she should compete at fourteen," she told ABC News.
Speaking from experience, Comaneci says, "It's a lot of work to be able to be so good at such a young age."
Fangda Wan contributed research to this story.