International pop star Shakira surprised fans when she joined the Mexican rock band Maná for a live duet of its song "Mi Verdad," Billboard reported. Shakira showed off her slim post-baby body just eight months after giving birth to her second son, marking her first live performance of the year.

Shakira surprised fans when she walked onstage at the Palau Sant Jordi Stadium in Barcelona, Spain. She sounded great and looked even better in a short, black mini dress that showcased her trim waist and toned legs and arms, according to fan-shot footage.

The pop star is a Barcelona resident, living in the city with her longtime partner, soccer star Gerard Piqué and their two sons, 2-year-old Milan and 8-month-old Sasha, according to Latina. Her surprise appearance at the Maná concert was her first performance of 2015 after giving birth to Sasha in January, and she teased the surprise with a photo on Instagram.

"Came to surprise some friends tonight!" she captioned the shot of her holding her finger up to her lips in a "shh" gesture.

The mom of two is keeping busy by posting adorable photos of her little boys on her Instagram, and she's gearing up for her next project, Entertainment Tonight reported. She's slated to star alongside Jason Bateman and Ginnifer Goodwin in the 2016 Disney animated film "Zootopia." Shakira will lend her voice to give life to a character in the film named Gazelle.

Watch Shakira's performance and see her Instagram post below.

 Came to surprise some friends tonight! Vine a sorprender a unos amigos esta noche! Shak

A photo posted by Shakira (@shakira) on Sep 6, 2015 at 1:36pm PDT