R *ihanna * has opened up to *Oprah Winfrey *, below, about the assault that ended her romance with *Chris Brown *, confessing she felt humiliated and embarrassed after the singer beat her up on the eve of the 2009 Grammy Awards.

Both stars pulled out of their planned performances at the music gala at the last minute after the bust-up and Brown was later charged with assault.

He publicly apologised for his actions, which left the Umbrella singer sporting a black eye and swollen lip, and was ordered to serve hard labour and probation.

Brown was also told he had to keep his distance from his ex, but that restraining order was lifted last year, allowing the pair to get together in the studio and record two new tracks.

In a candid new interview for Winfrey's Oprah's Next Chapter show, which will air in the US on August 19, Rihanna admits the drama after her fight with Brown put her in a very dark place.

"It was embarrassing. It was humiliating. I lost my best friend," Rihanna said. "I was super duper afraid of the pedestal that comes with fame," she added.