WATCH: Ariana Grande Brings Lady Gaga to Her Feet with AMA Show-Stopper John Shearer / Invision / AP Ariana Grande performs on stage at the American Music Awards at the Nokia Theatre L.A. Live on Sunday, Nov. 24, 2013, in Los Angeles. Regarding her performance at Sunday night's American Music Awards, Ariana Grande tweeted, "That was the most nerve wracking thing ever." It also happened to be the most electrifying performance of the night, bringing Lady Gaga to her feet and leaving Justin Bieber "honestly speechless" (but with enough feeling in his thumbs to tweet his stunned approval). The 20-year-old singer appeared on stage in a red sequins dress, and in a stripped down performance that refreshingly for a major awards show didn't involve actual stripping, she belted into a 50′s-era microphone a ballad from her album Yours Truly that sounded as if it had been channeled straight out of Motown's heydays. Grande tweeted to her fans after the performance, "I love you guys so so so much. that's all I've been thinking. thank you times a million 💕" Judging from the wave of congratulatory replies from fans and celebrities alike, the feeling was mutual. MORE: Taylor Swift, Justin Timberlake Win Big: The Best Moments of the American Music Awards