Swift, decked out in a gleaming pink-and-white striped dress, started the performance backed by a giant, glittery butterfly, before taking the stage -- where she was joined by Urie, rocking a matching burgundy suit and pink pants.
Flanked by a dozen backup dancers, also clad in shades of pink, the joyful performance concluded with a bombastic pyrotechnic display that really set the bar high for future Voice performances.
Swift's latest single dropped last month after weeks of buildup and teasing with cryptic Instagram posts and a mysterious countdown clock that whipped fans into a frenzy over her new music.
She performed the song live for the first time on TV as she opened the 2019 Billboard Music Awards back on May 1, where she was again joined by Urie, as well as a pink pastel drum line and a slew of backup dancers who brilliantly adapted the song's prismatic music video for the stage.
On Tuesday, Swift was one of several big stars to grace The Voice's big finale, including K-pop super group BTS, and the Jonas Brothers -- which is notable for the fact that, long ago, Swift dated Joe Jonas.
Recently, Swift sat down with Ellen DeGeneres on her daytime talk show, and admitted that she regretted putting Joe "on blast" back in 2008, when she was 18 and had appeared on Ellen to promote her latest album, Fearless.
"That was too much," Swift, now 29, told DeGeneres. "We laugh about it now, but that was mouthy, yeah, some teenage stuff there."
Check out the video below to hear what Swift has said about the Jonas Brothers singer, and the part he played in helping her write one of her songs.