A partition mounting system a system mitigates or eliminates sag, or gaps, between an installed curtain and an abutting surface such as a wall or ceiling. The system accomplishes this in a manner that avoids permanent damage to the wall or ceiling surface. A clamp is mounted between an erected pole and a nearby wall, window, or other surface. The clamp interfaces with a head that urges the curtain against the wall over the length of the head, using the pole and wall for leverage. In this manner, the effectiveness of an installation is increased, by reducing or eliminating gaps in the curtain along the wall.