A fire sprinkler support assembly includes a leg configured to extend transverse to each of a pair of adjacent parallel spaced beams. The leg includes levered clamp assemblies that are configured for connecting and supporting each end of the leg to a corresponding one of the beams. The levered clamp assemblies include a first plate and a second plate, each plate configured to straddle the beam. The levered clamp assemblies also include a lever assembly. The lever assembly includes a rod passing through corresponding rod openings in the first and second plates, and a lever pivotally connected to one end of the rod. The lever includes a cam surface disposed adjacent to the first plate. The lever assembly is configured to reduce spacing between the plates upon actuation of the lever, whereby the leg is secured to the beam.