Swift released the track at the stroke of midnight on May 26.
The crowd got quite the treat, as it was the first time the duo performed the track together on stage. What's more, fans in attendance also got a first-look at the remix's music video, which was released wide later that night. Swift has two more shows at MetLife on Saturday and Sunday before the tour heads to Soldier Field in Chicago, Illinois next weekend.
Earlier in the day, the 33-year-old Midnights singer told Spotify that it was the 23-year-old rapper who reached out to collaborate.
"Collaborating with Ice Spice on 'Karma' was one of the most natural things," Swift said in an audio snippet, shared by Spotify. "She reached out through her team, just kind of saying, 'Hey, Ice has been a big fan of Taylor’s since she was a little kid, would love to collaborate if that was ever something that came about.'"
And the feeling was mutual.
"I had been listening to her nonstop, like getting ready for my [Eras] tour, I was just listening to Ice Spice constantly," revealed the "Anti-Hero" singer. "So I immediately got her number and said, 'Hey, would you wanna do your version of 'Karma'? Do you relate to this?' So she jumped in headfirst."