Studio 54 Reopens for One Night -- Old People Flock in Droves

Everyone who was anyone hit Studio 54 in NYC last night for a special ONE NIGHT reopening of the club that defined the '70s ... athletes (retired), porn stars (retired), rockers (ok, still awesome).

With stars like Keith Richards, Susan Lucci and Clive Davis ... the only white stuff on the tables this time around was probably metamucil.

The event was sponsored by Sirius XM Radio -- and everyone who rolled in and out of the place told us the party kicked ass.