Where: First Annual Diamond Ball at The Vineyard, Beverly Hills, Callifornia
What She Wore: King of evening wear Zac Posen off the shoulder gown from his Fall 2014 collection. Styled with Chopard.
Verdict: Oh my Riri. She killed it. She rocked it. She totally nailed it. The colour is spectacular on her and she even looks better than the model who wore it on the runway. Zac Posen + Rihanna = One glamorous look.