You can't keep a Bad Gal down! Rihanna was back outside and dancing the night away when she made a surprise appearance at her best friend's birthday party. Source: Matteo Prandoni & Sansho Scott/BFA.com / Courtesy of AWGE As usual, all eyes were on Rihanna when she pulled up and popped out at Manhattan's Pergola restaurant in the early hours of Monday morning. TMZ reports she was attending at a private birthday bash that had been going for some time, but things really turned up as soon as she walked in.