The beaming bandmates -- Jungkook, J-Hope, Suga, V, Jimin, Jin and RM -- faced off with Fallon in a Fortnite dance challenge, where they did their best to recreate some of the dances performed by the animated characters in the mega popular video game.
As it turns out, all the guys of BTS are way better dancers than Fallon, but it was still fun to watch him try and keep up.
From "The Worm" to "The Robot," Fallon and BTS did an admirable job keeping up with the Fortnite avatars. Even when they all stood in a line to pull of "The Floss," they all had a great time -- except maybe for Fallon, who could barely keep up and then just fell over.
The segment wrapped up with BTS showing Fallon some of the most basic choreography from their "Idol" dance, and, well, let's just say it doesn't look likely that the 44-year-old star will be joining them during a performance any time soon.
The boys later sat down with Fallon, where they were met with a cacophony of a cheering, screaming and clapping from their fans in the audience as they each introduced themselves and goofed around with each other on the interview couch.
Fallon chatted with the group about their visit to the United Nations on Monday where they delivered a three-minute speech encouraging young people to stand up for their convictions and beliefs, which RM summarized with the phrase "speak yourself."
RM opened up about the experience with Fallon, explaining that the phrase is "about speaking for yourself instead of letting other people speak for you."
While BTS is used to playing showing in front of tens of thousands of screaming fans, RM admitted that appearing in front of those in attendance at the UN had his heart racing.
"I was like, so nervous. I was holding up the papers and you can see I was like, shaking," RM shared.
They also opened up about what they are hoping for in their futures, and RM explained, "We want to stay humble and enjoy the ride."
Although Suga had a more immediate goal in mind: "Go to the GRAMMYs."
The suggestion was met with resounding approval from the fans in the audience, and Fallon seemed fully on board.
"We can make that happen. Let's make that happen. #BTSGRAMMY right now!' Fallon told his viewers.
Closing out the night, BTS took to the Tonight Show stage for yet another incredible performance of their hit single "Idol," that absolutely tore the roof off.