The famous foursome joined other celebrity guests at the fancy affair, including John Stamos, Lance Bass and Ryan Phillippe.
The night before, Kim celebrated her 34th birthday at Las Vegas' Tao nightclub with her close family and friends.
The birthday girl wowed in a plunging white dress for her special night out, showing off plenty of skin and cleavage on the red carpet. She accessorized with black heels, diamond earrings and slicked back 'do.
Kardashian was also joined by Kanye, mom Kris Jenner, sister Khloe, BFF Jonathan Cheban, makeup artist Joyce Bonelli, Simon Huck, Malika Haqq and more at the Sin City soiree.