SHANGHAI -- This summer has seen an explosion in the popularity of e-sports in China's international metropolis of Shanghai, which is striving to build itself into a global e-sports center.

On Tuesday, the Main Event of 2019 The International (TI9), the largest Dota 2 tournament, officially kicked off in Shanghai's Mercedes-Benz Arena, the first time for this international event to be held in Asia. Sixteen renowned teams from all over the world gathered, joined thousands of esports enthusiasts at the event.

Books on e-sports were also in a large demand during the recently-closed Shanghai Bookfair.

According to statistics, the total income of China's e-sports industry currently ranks second among all countries, and Shanghai is one of the cities where the industry is most developed.

In recent years, Shanghai has also introduced several policies to support the development of e-sports, including a pilot athlete registration system.

"The e-sports industry is gaining a higher profile in China, which can be observed from people's interest in TI9," said Xiao Hong, CEO of Perfect World, which helped organize the event. "There are an increasing number of audience members who are curious about e-sports and have great consumer potential."

A large number of e-sports products were sold during the 17th ChinaJoy, an annual digital entertainment exhibition held in Shanghai.

Despite the controversies surrounding e-sports, the industry has become quite mature in Shanghai, according to Dai Yanmiao, associate professor at the Shanghai University of Sport, who is also the author of the book "A Brief History of E-sports: From Video Games to Sport."

He pointed out that the professionalization of e-sports in Shanghai started quite early and could be traced back to 2005, when Team WE, one of the first professional e-sports clubs, was established there.