Rihanna surprised Jay-Z fans in London over the weekend at the Yahoo! Wireless Festival when she joined him onstage for their hit song “Run This Town.” The 43-year-old rap superstar and entrepreneur released his latest album, “Magna Carta Holy Grail,” last week, and it is already No. 1 in the U.K.

Jay-Z rapped a number of his latest songs during the three-day festival, and was also joined by artist Justin Timberlake. They performed hits from Jay-Z’s new album and Timberlake’s album “The 20/20 Experience.”

But when Rihanna hit the stage, the 60,000 audience members went into a frenzy. The 25-year-old beauty wore a black silk skirt by Gareth Pugh, a white cutout crop top, Balenciaga Arena sneakers and accessorized with custom Jennifer Fisher body chains and a beanie.

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Rihanna and Jay-Z Tumblr
Rihanna
Rihanna and Jay-Z Tumblr
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Rihanna backstage after joining Jay-Z Instagram

Other big names who headlined the three-day event include Rita Ora, Kendrick Lamar, A$AP Rocky and Nas.

Meanwhile, Jay-Z recently had a candid interview on New York radio station Hot 97 with radio host Angie Martinez, and was asked about Rihanna and her on-and-off again relationship with Chris Brown.

“That’s not my place [to interfere]… I can’t control the outcome of her life. I can’t intervene. I can give advice, if asked, you know, and that’s it. I can provide information, and then life has to play out. Life has to happen.”

But Jay-Z may not have to give her advice about Brown anymore, after the pair split earlier this year. The 24-year-old has since moved on with ex-girlfriend Karrueche Tran. Rihanna has been enjoying the single life, partying just last week with race car driver Lewis Hamilton. Hamilton recently split with his girlfriend of nearly five years, “X Factor UK” judge Nicole Scherzinger.