Jackie Chan couldn't resist laying a big, fat kiss on Brett Ratner last night.

As the "Rush Hour" star and the film's director posed for paparazzi outside kosher hotspot Prime Grill, Chan gave Ratner a birthday kiss. Brett celebrated his b-day dinner at the restaurant with his grandmother -- the one spotted shopping Melrose Ave. with Paris Hilton -- and the heiress herself, wearing her good bra for the occasion. Hilton's spring fling, Josh Henderson, was seen later in the evening ... leaving Chez Paris.

Also at the restaurant were Joe Francis, "Buffy" star Michelle Trachtenberg and fellow WB alum, James Van Der Beek.

TMZ also spotted Nicollette Sheridan heading to Mr. Chow, where one photographer confused her with that other blonde Chow-hound, Sharon Stone -- and Nicollette didn't sound flattered. Audrina from "The Hills" was caught at Hyde, though unlike fellow MTV reality star Jessica Smith, she opted for a passenger seat after a night of partying.