APink's Eunji and her hoobae Seungkwan from Seventeen perform an impromptu yet amazing duet in Mnet's karaoke.

The friendly Eunji abruptly invites Seungkwan to perform a duet with her after seeing Seventeen members waiting outside the karaoke room. The surprised Seventeen's main vocalist is very honored and go with her. Eunji picks 4men ft. Lee Young Hyun's "Live In The Memories" and perform a mind-blowing duet together. The sunbae-hoobae's beautiful harmony and smooth high notes impress their fans.

Fellow Seventeen members, S.coups and DK are also amazed by Eunji's singing, while the Apink member praises Seungkwan "Seems like you've prepared" and such. What an outstanding duet for an impromptu performance! Watch below: