Frank Ocean's cancellation of his headlining FYF Fest performance is just one of the ways he's disappointed fans recently (where's the album?), but luckily, the proven showman Kanye West stepped in for Ocean, and made sure to make up for his absence with a special surprise for the crowd -- Rihanna.

RiRi made two appearances during Ye's set, first for their monster-hit, "All Of The Lights," and later for an intimate performance of "Four, Five, Seconds," where the singer got right up in the faces of the audience.

Overall, we're sure even the biggest Frank Ocean stans left satisfied.

Some fan-shot footage has made its way online, check it out below.