The FYF Festival held in Los Angeles Sports Arena and Exposition Park on Aug. 22 and 23 was headlined by Kanye West and Morrisey, respectively. Unexpectedly, Rihanna surfaced from the audience and joined Yeezy during his performance. However, some reports suggest that her surprise appearance might be part of one of his plans.

It all happened when Kanye West performed Rihanna's hit "FourFiveSeconds," as revealed by BillBoard. The song was co-written and co-produced by famous The Beatles member Paul McCartney.

As the story continued, West reportedly found Rihanna among the crowd and one of the event's crew passed the mic to the "Diamond" singer as she sang the chorus. Rihanna then took the mic and belted the notes from the audience.

"Make some noise for Rihanna in the crowd," West shouted, as we quote from the source.

Much tothe crowd's surprise, Rihanna finally took the stage with West on the last 10 minutes of his performance time. They marked the event by performing Yeezy's single "All of The Lights" from his newest album "My Beautiful Dark Twisted Fantasy."

During her cameo duet, Rihanna sported a messy ponytail and a huge hoodie outfit. Her "not so ready" outfit suggests that her performance might be unplanned, as Vanity Fair noted. But, should the element of surprise be staged, the site believed that Yeezy might be behind not just the singer's "cameo" appearance, but Ocean's decision to pull out his slot on the musical event as well.

Kim Kardashian's husband has yet to comment about the news.

Meanwhile, some fans of Frank Ocean were reportedly disappointed after his cancellation.

"Frank is our favorite. We've seen Kanye West several times," a fan from Richmond, VA. told the Los Angeles Times. "We've never been to L.A. but we would have picked a different city," the fan added.

We previously reported that Frank Ocean cancelled his performance "to his own terms" 2 days prior to the event, organizers announced on Thursday. Notably, Yeezy was already present and to the rescue as replacement.

Here is the video for Kanye West and Rihanna's performance at the FYF Fest, courtesy of Youtube user Spencer Clement.