As the most popular and commercially successful professional sport in North America, American football is also making strides in China but still trails in grassroots popularity and public recognition.

Since first appearing in China in the early 2000s, the sport has enjoyed loyal support from its 3 million fans in the country.

But a lack of understanding of its complicated rules, as well as expensive outfits and equipment, has hampered its progress in China.

Without a nationwide professional league, the amateur American Football League of China became the sport's top-level competition in the country when its first official season kicked off in July 2013.

The league boasts eight teams from major cities including Beijing, Shanghai and Chongqing.

A less physical version of the game, flag football, in which defenders are not allowed to stop offenders by tackles or clashes, was introduced to Chinese colleges in 2003.

It has been played at more than 80 Chinese universities.

Still, the game remains in its infancy in China without being included in the country's State-run sports administration system.