Los Angeles: R&B star Rihanna joined rapper Eminem on stage at the 2014 Lollapalooza in Chicago.
Eminem was headlining the music festival when he brought out 26-year-old Rihanna as his special guest, suggest reports.
The duo performed their two collaborations - `Love the Way You Lie` and `The Monster`.
Rihanna also took over the vocals for Eminem`s 1999 hit `Stan`, which originally featured Dido.
The show marks Eminem`s first headline set at Lollapalooza since 2011.
Both artists are set to go on the road together for their `The Monster Tour: Eminem X Rihanna`, which will kick off on August 7 in Pasadena, California.
`The Monster` was recently nominated for Best Male Video, Best Collaboration and Best Direction at this year`s MTV Video Music Awards.