ET was first to report that the couple broke up after six years of dating.
The 33-year-old singer resumed her The Eras Tour at Raymond James Stadium in Tampa, Florida, where singers beabadoobee and Gayle opened the show. Swift will also perform in Tampa (whose Hillsborough County was temporarily changed to "Swiftsborough" County) on Friday and Saturday.
And a video from the concert shows Taylor performing her hit, "Cruel Summer."
Swift's Tampa dates also started with a little flub from the singer, who accidentally announced Thursday's opener as Gracie Abrams when it was actually Gayle.
"Thirteen is a number that has defined all kinds of lucky things for me," Swift began before apologizing for the mix-up. "But tonight it is actually also the exact number of brain cells that I have, because earlier, I told you that Gracie Abrams opened the show, that is not correct."
She continued, "That is absolutely not correct. Gayle opened the show and she was phenomenal, and I feel so awful."
Swift capped the apology off by singing the "abcdefu" performer's praises and promised to get her tour mates "lots of presents" to make up for the mistake.
Swift also debuted a new dress for her "Enchanted" performance, sporting a sparkling gown by Eli Saab couture, which featured flower petal-like embellishments.
She later rocked a new green two-piece number for her Folklore era, which included a long, draped cape. On top of that, she sported a new orange fringe dress for her 1989 set.
As for Swift's epic stage dive she's been doing night after night, this time she took an extra second to make sure it was safe before diving head-first into the stage at the stadium.
In addition to her many outfit changes, she also performed two surprise songs for the sold-out crowd -- "Speak Now" off her 2010 album by the same name, and "Treacherous" from 2012's Red.
On Saturday, ET exclusively reported that Swift and Alwyn, who were notorious for keeping their relationship private, called it quits a few weeks ago. A source told ET that the split was amicable and "it was not dramatic." ET also learned that "the relationship had just run its course. It's why [Alwyn] hasn't been spotted at any shows."
While the split sent shockwaves around the world and left Swifties in disbelief, it's possible the songstress hinted at the split in her Eras Tour setlist, after eagle-eyed fans noticed she changed it up for the show in Arlington, Texas, on March 31. Instead of performing "Invisible String" -- which is believed to be a love song about her relationship with Alwyn -- Swift played "The 1," which details a breakup. Both tracks are from her 2020 album, Folklore.
Following news of her split, Swift was spotted grabbing dinner in New York City with her friend and longtime collaborator, Jack Antonoff, and his fiancée, Margaret Qualley.
Videos and photos shared on social media show Swift smiling as she stepped out for dinner with the couple at Via Carota restaurant in downtown Manhattan, just blocks away from Cornelia Street, which was the inspiration for one of Swift's songs on her Lover album -- fittingly named after the street where she once had a home -- and believed to be inspired by Alwyn.
A source later told ET that the couple's breakup was initiated by the pop star.
"Taylor and Joe are in totally different places in their lives right now," the source told ET. "It was more of Taylor's decision to break up, but both of them realized that they weren't completely right for one another. They had been together for such a long time and were spending so much time together, but their personalities were just too different. Joe is more introverted, shy and quiet."
"She's very focused on touring and her career right now," the source added. "Taylor has nothing but respect for Joe and really loved and enjoyed all the time and memories she shared with him. They had a deep connection and she really appreciated that. She hopes they can be friendly in the future."
As for what's next for Alwyn, the 32-year-old actor is staying busy abroad. He recently traveled to Hungary to begin principal photography on his upcoming film, The Brutalist, opposite Adrien Brody, Felicity Jones and Guy Pearce.