Megan Thee Stallion surprised BTS fans as she appeared on stage to perform the chart-topping "Butter" during the "Permission To Dance" concert held in Los Angeles on Sunday.

Many fans took to Twitter to share clips from the concert where the 26-year-old rapper made a surprise appearance on stage after she was spotted at the rehearsal earlier that same day.

A fan shared a photo featuring the rapper with the BTS boy band members rehearsing for the show and captioned it, "Megan Thee Stallion was reportedly spotted rehearsing tonight at BTS’ Permission to Dance concert in LA."

After a couple of hours, fans witness the powerful performance of Stallion and all seven BTS members - Jungkook, Jin, RM, V, Suga, J-Hope and Park Ji-min.

Another fan shared a video featuring a moment when Min Yoon-gi, popularly known as Suga, pointed at the rapper while singing, "got that right body and that right mind" from "Butter" music track, which was released in May.

One of the fans shared a photo of Stallion and Jungkook performing closely. In the photo, the rapper could be seen wearing a pink outfit while the 24-year-old singer donned a complete white attire.

A netizen also shared a video of the BTS members and the rapper as they left the stage after their performance. In the video, RM says, "Make some noise for the beautiful Megan Thee Stallion" and the audience responds with cheering.

Fans took to the comments section of this video to share their reaction.

One of the fans noted, "HER OUTFIT IS SO CUTE" while another wrote, "I can see jk and namjoon rushing over to help megan down the stairs."

Previously, Stallion called off her performance with BTS due to personal reasons. She was supposed to perform with the boy band at American Music Awards, last week.

"Hotties I was so excited to go to the @AMAs and perform with @BTS_official, but due to an unexpected personal matter, I can no longer attend __ I’m so sad!" she wrote on Twitter, Nov. 20. "I really can’t wait to hit the stage with my guys and perform #BTS_Butter real soon!"

While many fans were upset at that time, it seems that the rapper has given fans a pretty good surprise this time. The next event of the "Permission To Dance" concert is scheduled for Dec. 2 at SoFi Stadium, California.

South Korean boy band BTS perform during the 2020 MTV Video Music Awards
BTS is back live in action with their "Permission To Dance" concert in LA. MTV / -