Laser action of HgCl* was observed using an electron-beam-controlled discharge to pump a gas mixture of Hg/Cl2/Ar. An order of magnitude in the fluorescence enhancement was obtained. This gives an excitation efficiency by controlled discharge to be a factor of about 2 higher than that by direct electron-beam pumping. In addition to the previously reported 5576-Å laser transition of HgCl*, a strong transition at 5584 Å was also observed.