“This is something you could see only in venues where popular rock band performances are held. Some fans follow their nationwide tour. In my experience, there have been no Asian singers who have had such enthusiastic fans.”

Tickets for the much-anticipated concert sold out in less than 20 minutes.

New York was the last stop on BTS's North America tour, which is part of their world tour. The North American tour began on September 5 with their concert at the Staples Center in Los Angeles. Some 20,000 fans flocked there to see the K-pop superstars.

On Saturday, the group performed at Citi Field.

After tickets had sold out, a number of fans camped out near the stadium to get a head-start in the rush to be the first ticket holders to get into the general admission “pit” area. BTS fans called the makeshift campsite BTS Village.

“The venue has a symbolic meaning,” Kim said, noting that holding a concert at the stadium means much more than just a performance. “It is the most frenetic concert I've ever seen.”

BTS is the first K-pop act to perform in the stadium.

According to Kim, Citi Field as a concert venue has a symbolic meaning for pop artists. World-famous artists, such as Paul McCartney and Beyonce, have performed there.

Fans in the stadium sang along with the superstar K-pop band during the concert, Kim said. They sang entire songs together, not just parts of songs, which he said wowed him.

“I've attended many concerts, both K-pop and American music concerts. In terms of fan enthusiasm and fever, this one is unrivalled,” said Kim.

Fans, including a variety of age groups, from teens to parents and adult K-pop enthusiasts, flew in from all across America, and those who were from distant cities camped near the concert venues.

In a media interview, pop culture critic Kang Moon said the BTS North America tour concert means a lot. “There have been other K-pop groups who had concert tours in the region. However, BTS is completely different from them,” he said, adding that BTS is a game changer.

“Before BTS, K-pop had never been mainstream. But BTS broke through into the mainstream. When you look at the venues of their concerts, they were where major mass culture events had taken place. This means BTS entered the mainstream and became part of it.”

Kim said BTS was able to achieve much more than what other K-pop acts had, thanks to their strategy.

“Unlike other K-pop acts, BTS tried to present themselves as they are and their genuine side, without trying to make up or overstating themselves, which I think appeals to US fans,” Kim said, when asked about the group's key to success in going global. “The fact that they are strong at Hip Hop and R&B would have appealed to the US fans.”

The seven-member K-pop band will head to Europe to continue their world tour and will hold a dome tour of Japan in November.

The New York City Transit Authority assigned more metro trains to the route connecting to Citi Field and informed fans of this through their official account on twitter, ahead of the event.

With much enthusiasm, the group kicked off the Citi Field concert with their latest song Idol, followed by previous hits including DNA, Fake Love and MIC Drop.

"We couldn't believe we finally came here to Citi Field. One of our dreams has come true," BTS said during the concert.

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