The media-friendly showman became a national hero when he earned the country's first ever gold medal in the men's -100 kg class at the Beijing Olympics, 44 years after Mongolia first competed in a Games.
A burly 28-year-old with a slight squint and cauliflower ears, Tuvshinbayar is now hoping to repeat that success in London, likely to be his last Games as a serious competitor.
"Of course, we athletes are competing for our country. And I'm competing to be an Olympic champion again, and have my country's name heard across the world," he told Reuters.
Tuvshinbayar only took up judo at the age of 18, after seeing the Asian Championships on television.
But like many of Mongolia's nomadic herders raised on the vast steppe, he grew up wrestling, as a young child with his family's livestock, and later in matches at traditional festivals.
He even refers to his chosen sport as 'judo wrestling,' which may account for a certain heavy-handedness in his style.
"In Mongolian families, there is nobody who is not interested in traditional wrestling. Since I was a young child, I wrestled, and that's where the preparation for becoming a judo wrestler started," he said.
"There are a lot of similarities. Wrestling is just wrestling," he added with a lop-sided smile.
Almost 400 contenders from 134 countries, up from 96 in 2008, will battle it out in the seven weight categories for men and women during seven days of competition at London's ExCel exhibition centre.
Khashbaatar Tsagaanbaatar has high hopes for the men's -66 kg class, while Munkhbaatar Bundmaa is pitted for a medal in the women's -52 kg class, having taken golds in both Paris and Moscow Grand Slams in 2011.
Despite traditional heavyweights like Japan looming large, petite 26-year-old Bundmaa is unperturbed.
"I'm confident in myself. Going to the Olympics is not a small thing, and I will come back with a medal," she said.
Mongolia is also throwing its weight behind freestyle wrestling, boxing and shooting, all of which involve the traditional combat and hunting skills that 800 years ago helped build an empire that stretched as far as Europe.
"In our country, four kinds of sports have developed well: judo, boxing, shooting and wrestling," said Demchigjav Zagdsuren, president of the National Olympic Committee.
"At the last Olympics and in previous games, it was in these sports that we won medals. Our goal for London is to get at least four medals in these."
Once-impoverished Mongolia saw its economy grow by over 17 percent in 2011, thanks mainly to foreign investment in the huge mineral resources lying beneath its grasslands and deserts.
Rio Tinto, which runs the country's massive Oyu Tolgoi copper and gold project, sponsors the Mongolian Olympic team, and is providing Mongolian gold for the medals at London.
The country's growth has meant dramatic increases in sports funding, filling a vacuum left by near economic collapse following its split from the Soviet Union in 1990.
"Mongolia is now growing faster and sports are developing in step with the country," said Zagdsuren.
With considerable national pride resting on his broad shoulders, and a generation of younger athletes stepping up to fill his shoes, Tuvshinbayar is philosophical.
"If you think of it as pressure, it's pressure. If you don't, then it's not. Athletes should free themselves from that kind of thinking and try to find the joy in what they do," he said.
"If I had any doubts, I wouldn't be able to succeed."
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