Taylor Swift, Avril Lavigne perform "Complicated" at concert

Pop stars Taylor Swift and Avril Lavigne shared the stage to perform the latter's hit song, "Complicated", at the "1989" concert in San Diego, California.
Lavigne, 30, who returned to the stage for the first time last month since revealing her battle with Lyme disease, took to Instagram after the performance to share her excitement, reported People magazine.
"Such a Pleasure to perform "Complicated" tonight with @taylorswift on her #1989 world tour! She ROCKS!" the singer wrote alongside a picture of her and Swift.
The 25-year-old "Bad Blood" hitmaker also took to social media to acknowledge Lavigne's performance.
"So incredible sharing the stage with @AvrilLavigne! 'Complicated' is such a brilliant pop song and I just love her," Swift tweeted.

The concert took place almost a week after Lavigne's fans were not happy when a post comparing Swift's interactions with her fans with other stars' meet-and-greets made the rounds on Tumblr.
"We've been texting all week and we finally got to meet today and she's so cool. She's so sweet, which I love, when I find out that one of my favourite artists is also super amazing as a person," Swift told the crowd.