Watch: Taylor Swift Joined by Avril Lavigne and OMI at San Diego 1989 Concert
Following a understanding with Swift on social media earlier this week, Lavigne excitedly stepped on stage to perform a duet of her 2002 breaking hit "Complicated" for thousands of screaming fans at Petco Park.
"So incredible sharing the stage with @AvrilLavigne!" Swift tweeted after the performance. "'Complicated' is such a brilliant pop song and I just love her."
The overblown "beef" arose from Swift liking a fan's Tumblr post comparing her loving meet-and-greets with fans to other artists, including Lavigne, Entertainment Weekly points out. Lavigne caught wind on Twitter and replied, "Comparison is judging and judging a person does not define who they are it defines who you are. We all Love our fans." She later tweeted a photo collage of her posting with happy fans. "So let's keep it all about the love and stay positive," the singer wrote.
Meanwhile, Swift also welcomed Jamaican singer OMI for a performance of his inescapable and wildly catchy hit "Cheerleader." Watch the performance below.
Other surprise guests on Swift's current 1989 tour have included Selena Gomez, Fifth Harmony, Justin Timberlake, Fetty Wap, Nick Jonas, The Weeknd and Lorde. The trek continues Sept. 4 in Salt Lake City.