Kanye Headlines FYF Fest Give it Up for Rihanna!!!

8/23/2015 6:28 AM PDT

Kanye at FYF Fest -- Give It Up for Rihanna!!! (VIDEO)

People who went to FYF Fest Saturday night got a bonus when Kanye performed ... Rihanna.

She hopped on stage twice, once to perform "All of the Lights" with Kanye, and a second time to perform "FourFiveSeconds with him."

This could have been a tough crowd ... Frank Ocean, who was scheduled to headline, dropped out and Kanye took his place.  But by the end it was, "Frank who?"