For the past 21 years, the Barnstable Brown Gala, a benefit party held on the eve of the Kentucky Derby, has been the hottest ticket in Louisville and a magnet for all the Hollywood types in town for the races. But lately, its guest list has become a bit wilted (last year the highlights were Hugh Hefner with his bevy of girlfriends, and MTV’s Heidi Montag and Spencer Pratt). This year the institution will have a run for its money: Briar Rose Estate, a historic plantation that was recently bought by San Diego businessman Gabriel Giordano, is planning its own over-the-top bash, replete with a trotting exhibition, a horse auction, flowing mint juleps and a heavy Tinseltown presence. With invites going out to A-listers, top professional athletes and socialites, the Derby weekend’s real race seems to be between these rival parties.

horse: Andy Lyons/Getty images