To celebrate her 29th birthday last Saturday, Grey's Anatomy star Katherine Heigl opted for a low-key dinner with eight of her closest friends.

The group included Katherine's fiance, singer-songwriter Josh Kelley, and her Grey's Anatomy co-star, T.R. Knight, and met up at Nobu in Malibu, Calif.

Dressed down in a tweed blazer, with her hair pulled in a bun, Heigl sat between Josh Kelley â€" whom she will wed in a small ceremony December 23 â€" and T.R. Knight.

When the cake came, the entire restaurant joined in and sang "Happy Birthday, Dear Katie," a witness reports, adding that the cake even had sparklers on it.

Happy belated birthday to Katherine Heigl!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.