Over the weekend Zac Efron was just one of the party guests who attended Rihanna’s birthday bash! In the morning Rihanna attended, and performed at, the NBA All-Star basketball game in Los Angeles, California. The star sat next to Justin Bieber during the game.

Then, Rihanna headed to a private home in Beverly Hills, California where she ate red velvet cake and hung out with a number of famous party guests, including:

- Zac Efron
- Ryan Phillippe
- Mary J Blige
- Jay-Z
- P Diddy
- Christina Milian
- Joel Madden
- Snoop Dogg

We hope Rihanna had a great birthday party!

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