Kanye West performs at FYF Fest with surprise guest Rihanna

Kanye West's last-minute appearance at FYF Fest on Saturday yielded a special surprise: Guest singer Rihanna!

Late last week, Yeezy was confirmed to replace Frank Ocean as the headliner of the festival, which takes place over the weekend at Los Angeles' Sports Arena and Exposition Park. At some point during his performance, he handed the mic to Rihanna, who was sitting in the front row and later hopped on stage.

"L.A., make some noise for my n---- Kanye!" she shouted.

The two performed "FourFiveSeconds," the first single from Rihanna's upcoming new album, which features West and Paul McCartney, and the hip-hop star's track "All of the Lights," which features her and Kid Cudi.

West's pregnant wife Kim Kardashian attended Saturday's concert to support her man, bringing along sister Kourtney Kardashian and Kendall Jenner. She posted several pics on Instagram.